The primary MLD base in the Netherlands East Indies was MVK (Marine Vliegtuig Kamp, or Naval Air Station) Morokrembangan at the Marine Establishment (Naval Base) at Soerabaja on eastern Java. One of the largest seaplane bases in the world, it was a large complex purpose-built for amphibious operations in 1923. Before the base became operational on July 30, 1925, all previous naval air operations had been carried out from the ML air base at Tandjoeng Priok, outside Batavia on the western end of Java. The new location was also more convenient, since the KM’s East Indies Squadron also operated from Soerabaja.
Located just outside Soerabaja on the southwestern edge of Morokrembangan, Perak was the city’s primary civilian airfield. All MLD land-based primary flight training was also carried out here. It had two 3,000-foot runways and a KNILM hangar that were also used by the Dutch military throughout the East Indies campaign to provide the port, naval and seaplane bases with air cover. Although its facilities and ground personnel were officially under naval jurisdiction, the ML traditionally provided all of the fighter aircraft operating from Perak. The KM went so far as to order six Fokker C.V-D fighters in 1927; however, they were instead delivered to ML units in the East Indies.1
Located on the north coast of eastern Java on the mouth of the Krembangan River, the ME was sheltered by the large island of Madoera. Just west of the naval base lay Soerabaja’s vast commercial port, which handled thousands of civilian merchant ships annually. MVK Morokrembangan lay a short distance west of the commercial port, although the distance between it and the ME was not far.
Although the KM regularly dredged it, the harbor at Soerabaja was still shallow. Bare and exposed at low tide, a series of mudflats dotted the harbor and was deceptively concealed just beneath the surface at high tide. A channel leading to the seaplane base was usable at all times and clearly marked. However, without charts or local knowledge of the channel, it was impossible to know which side of the buoys to stay on. If one strayed off the step, the penalty usually involved having to be pulled off the flats by one of the base’s small harbor boats.
In 1939 and 1940, MVK Morokrembangan received a series of substantial modifications and renovations as the Dutch government attempted to strengthen the country’s armed forces. These efforts yielded a large number of new hangars, ramps, workshops and barracks. By the outbreak of the Pacific War, Morokrembangan had 24 hangars, concrete ramps, expansive workshops, transport cranes, underground fuel tanks and powerful radio facilities that let it easily communicate with distant corners of the East Indies and KM ships that were at sea.
Morokrembangan (with Perak Airfield in the background) was the largest and best-equipped seaplane base in the Pacific outside Japan or Hawaii.
Powerful radio facilities let Morokrembangan communicate with aircraft and base personnel at the farthest reaches of the NEI (photographs from Soerabaja 1900-1950 [2004], courtesy of Asia Major Publishers).
The base also received its first floating dock in 1932, further increasing its ability to maintain and service seaplanes operating from the base. And although none of the MLD aircraft taking part in the East Indies campaign was amphibious, the MLD was still able to pull them out of the water quite easily for major repairs and comprehensive overhauls. This was done using hoists or special trailers built by the Braat Steelworks in Soerabaja that were towed by Caterpillar tractors.
But despite all of these facilities, Morokrembangan was far from ideal in more than one respect. In addition to the mudflats described earlier, pilots were forced to negotiate and compensate for fast-moving currents during landings and takeoffs, which made their job that much more difficult. Its location almost directly adjacent to the ME also often put air traffic near or directly in the middle of sea traffic entering and leaving the naval base and commercial port. As a result, the area was always congested. And finally, its close proximity to the ME ensured that Morokrembangan would consistently remain a prime target for any land, air or sea attacks against Soerabaja. But in spite of these drawbacks, it was a well-built complex that many aviation experts regarded as the largest, best-equipped and most modern seaplane base in the Far East outside Japan.
Prior to May 1940, most MLD pilots,2 aircrews, officers and enlisted men were trained either at the De Mok and De Kooy seaplane bases or Willemsoord Naval Base in Holland. Pilot trainees first learned to fly in standard land-configuration planes before making the transition to seaplanes. Primary, intermediate, advanced and formation flight training took place in Holland. As most seaplane pilots were assigned to units in the East Indies, a majority of the cadets were then transferred to Morokrembangan for operational training.
Ryan STM-S2 trainers in formation with Fokker T.IVa seaplanes attached to the MLD flight training school at Morokrembangan (photograph courtesy of San Diego Aerospace Museum).
After the occupation of Holland, the MLD relocated all flight training to Java and initiated an extensive network of training programs at Morokrembangan. In addition to primary, intermediate and advanced seaplane flight training, they also included technical studies for all branches of the MLD. Besides training personnel for the East Indies, a number of Dutch personnel evacuated from Holland were sent to Java to complete their flight training before returning to Europe.
The MLD Flight Training School operated a total of 10 Dornier Do. 15 “Whales” (not all operational), 1 Fokker T.IV, 6 Fokker C.VII-W, 10 Fokker C.XI-W, 40 Ryan ST and 5 Tiger Moth primary trainers. In addition, a small number of T.IVs were transferred from active service to the school. The STM-2 (land) primary trainers were based at Perak and the STM-S2 floatplanes went to Morokrembangan. Many of these aircraft were lost as the Japanese began bombing Java on a regular basis. As a result, the school was shut down in mid-February 1942 and transferred to Australia to avoid further losses of personnel and equipment.
Flight training in the East Indies greatly accelerated after the fall of Holland and was extremely intense. Prior to the attack on Pearl Harbor, there were approximately 60 European and Indonesian cadets undergoing training. Although the ML transferred four flight instructors to the school, they proved too few for the task at hand. As a result, the quality of training for many of the students suffered.3
To improve the pace and quality of its flight training program, the MLD hired 12 American flight instructors from the United States in 1941. Although all were civilians, they appear to have been ex-military or reserve pilots from the ranks of the USN and USMC.4 It is unclear how many were seaplane pilots as most were engaged in primary flight training. Soon after their arrival at Morokrembangan, the Americans dubbed the giant seaplane base “Little Pensacola” after the naval air station in Florida where many had undergone their own flight training.5
X-3 is serviced while attached to the flight training school at Morokrembangan; note the Fokker T.IVs moored immediately behind (photograph courtesy of André de Zwart).
Primary flight training began on the Ryan land trainers, followed by additional primary training on the Ryan seaplanes. Trainees then graduated to more advanced seaplane flight training on the Fokker C.XIV-W, Fokker T.IV and Dornier Whale.6 They completed operational training on the new Do. 24K-1s as these planes became available. A number of MLD pilots trained at Morokrembangan and Perak were later transferred back to England to fly Anson and Hudson aircraft with Dutch forces in exile attached to British Coastal Command.
To facilitate the substantial increase in the numbers of pilots and flight personnel undergoing training, the MLD recalled the Fokker T.IV seaplanes of GVT.11 from patrol duties at Balikpapan in mid-August 1940. The squadron’s reconnaissance duties over the Makassar Strait were taken over by ML Martin bombers operating from airfields on Borneo. It appears that the Fokker crews were transferred to one of the new GVTs then being formed with the Do. 24s.
As the threat of war with Japan grew, the MLD initiated a full-scale flight training program that included both European and Eurasian cadets (photograph courtesy of San Diego Aerospace Museum).
Three of the American flight instructors hired by the MLD in 1941 (l to r): Lt. John Russel (USN), Unknown (standing), William Eddy (civilian), Lt. Willard Reed (USMCR), Lt. 1st Class K. Holtz (MLD) and Sub-Lt. F. Beugeling (MLD) (photograph courtesy of Institute for Maritime History).
In a short time, the trainees, many of them reservists or teenagers just out of high school, had to absorb a vast amount of complicated information. Not all of it involved the mechanics of flight, but also how to differentiate weather formations, identify storm fronts and analyze water conditions to gauge landing conditions. These grueling flight and navigational exercises went on 24 hours a day, supplemented by continuous bombing and gunnery training. The latter took place either on a floating dock anchored in the Madoera Strait or the decommissioned destroyer Lynx, whose grounded hulk lay beached on a sandbar near the ME.
In contrast to their American and British counterparts, many regular MLD pilots in the Far East were older than average.7 This can be attributed, at least in part, to the MLD being a small, highly skilled peacetime force. Turnover in these types of close-knit organizations is rarely high in any country’s military. In addition, funding throughout the 1930s strictly limited the growth of the MLD, dictating that it remain a small force dominated by career men.
Like their American counterparts, combat experience among MLD flight crews was virtually nonexistent. Although many had logged large numbers of flight hours prior to the outbreak of war, it was still “on-the-job training” when the shooting started. Three KNIL fighter pilots were sent to Britain for training and operational experience in late 1940. However, two of them were killed in action in 1941, and only one returned to Java. Five more pilots were en route to Europe when the Japanese attacked Pearl Harbor, and they were recalled.
For their part, the British scattered a handful of experienced veterans throughout most of their air units. However, the most experienced were sent to combat zones in Europe and Africa. This meant that the bulk of the aircrews in the Far East were composed of young, inexperienced personnel straight out of training schools in Australia, East Africa, New Zealand and Rhodesia.8
The German invasion of Holland also cut off the MLD from its traditional source of personnel. As the total number of Europeans in the East Indies, women, children and senior citizens included, numbered fewer than 300,000, this forced the MLD to compete with the KM and KNIL for qualified technical recruits in a severely restricted pool of applicants. Although Eurasians and Indonesians were eligible to join the KM in every branch and capacity, few met the rigid educational requirements required to become pilots.9 As a result, the MLD was left with a substantially older, albeit well-trained, core of seaplane pilots.
In addition to courses for regular and reserve officers, training centers for air gunners, radio operators and mechanics also existed. An MLD mechanics and workshop training college for Indonesian recruits at Makassar was also expanded. A number of these men were evacuated before Java fell and formed the bulk of Dutch ground crews throughout the war.
One of the largest training programs was for radio operators. Although all its planes were in direct contact with shipboard and shore-based radio stations, one of the most severe shortages the MLD faced was a lack of trained operators. As radio equipment became standard on MLD planes throughout the 1930s, the first wireless operators were trained in Holland and shipped to Java to form the core of a specialized training program for aircraft and shore radio operators.
With the expansion of the MLD and occupation of Holland, this program was expanded, and a number of militia recruits trained. Still, the shortage remained so severe throughout the fleet that in early 1941, Admiral Helfrich ordered the formation of a separate communications branch of the MLD to meet the East Indies Squadron’s needs.10 Since the MLD had a surplus of junior officer pilots at that time, a number of these recruits were retrained as radio operators. To fill yet another void, all radio operators were also cross-trained as air gunners and flight medics.
Although men and material consistently remained in short supply, evacuees from occupied Holland and civilian volunteers from South Africa provided the MLD with a solid core. As seen earlier, from May 1941 on the MLD could also draw from the ranks of the VVC (Vrijwillig Vlieger Corps) or Volunteer Flying Corps, for new pilot trainees. These young men flew DH.82a Tiger Moth,11 Büchner Jungmann12 or Piper Cub13 training aircraft on weekend training flights. These reserves formed a valuable personnel resource for the East Indies air forces.
A contingent of navy pilot trainees had been evacuated from Holland in May 1940. After a brief period in England, they were transported to Java by ship, arriving in Batavia on November 21, 1940. They underwent advanced flight training at Morokrembangan before returning to England to form the nucleus of the Royal Air Force’s 320 Squadron (Dutch). They did not return to the Pacific and flew from British air bases throughout the war.
The crew of X-8; note the Indonesian crewman at a time when USN flight crews were strictly racially segregated (photograph courtesy of Nol Baarschers).
In addition to its comprehensive training facilities and workshops, all supplies, spare parts, engines and reserve aircraft were housed at Morokrembangan. There were also a number of older planes, including the older “D” and “T” planes, many of which were reactivated for duty in late 1941. Throughout the campaign, damaged seaplanes of all nationalities also came into Morokrembangan for overhaul and repairs, while new Dutch PBYs from the United States arrived to be made ready for operational service. Large numbers of American seaplanes from the Philippines also moved in and out of the base as the campaign progressed.
The crew of X-15 relaxes atop its plane at Bima Harbor in March 1939; at least two crewmen drink milk from coconuts (photograph courtesy of Nol Baarschers).
Morokrembangan remained free from air attack until February 3, 1942. The first attack was heavy, with 72 bombers and 44 fighters hitting the ME and nearby air bases. Allied fighters were unable to stop the attack, and that day at least 15 MLD planes were shot down or destroyed on the water. From that point Morokrembangan remained a prime target for the Japanese as they returned time and again to claim more MLD planes in an effort to reduce Allied air power.
There were four main secondary bases throughout the NEI, including MVK Priok at Tandjoeng Priok outside Batavia on western Java, MVK Ambon, MVK Tarakan and MVK Prapat on Lake Toba in Central Sumatra. Although all were officially considered major hubs, with the exception of Tandjoeng Priok, they were little more than built-up advance bases that were capable of carrying out major maintenance on MLD aircraft. For example, MVK Prapat was completed only just before the outbreak of war and had only a concrete ramp and barracks for aircrews. As with Morokrembangan, all were equipped with Caterpillar tractors and specially built trailers that let the seaplanes be easily removed from the water.
Activated on December 24, 1918, MVK Priok was substantially smaller than the main air station at Morokrembangan. Although closed upon the completion of Morokrembangan, Priok was refurbished and reactivated in 1940, as the MLD was rebuilt and strengthened. Situated just west of the civilian harbor, it featured two hangars capable of housing four flying boats, an underground fuel tank and a number of workshops; at maximum capacity, MVK Priok could handle 10–20 large seaplanes. Although small it benefited from the reliable, well-organized transportation network that the island of Java offered.
MLD Seaplane Bases December 1941. Legend: (1) MVK Morokrembangan; (2) MVK Priok; (3) Tjilatjap; (4) Lake Tjileuntje; (5) Lake Grati; (6) Brantes River; (7) Oosthaven; (8) Tandjoeng Pinang; (9) Klabat Bay; (10) Lake Toba; (11) Sabang; (12) Poelau Sambo (Riouw Archipelago); (13) NAS Selatar (Singapore); (14) Anambas Islands; (15) Natoena Islands; (16) Sambas; (17) Kuching; (18) Pontianak; (19) Ketapang; (20) Bandjermasin; (21) Balikpapan; (22) Telok-Bajor; (23) Tarakan; (24) Menado; (25) MVK Kalkas (Lake Tondano); (26) Makassar; (27) MVK Halong (Ambon); (28) Ternate; (29) Sorong; (30) Manokwari; (31) Kalabhai (Alor Island, Lesser Soenda Islands); (32) Koepang; (33) Roti Island; (34) Benooid Bay (Roti Island); (35) Bima (Soembawa, Lesser Soenda Islands); (36) Christmas Island.
The primary seaplane base in the eastern East Indies was MVK Halong, on the island of Ambon. Completed in 1939 and situated on the northern shore of Ambon’s enclosed inner bay, it was the largest MLD seaplane base after Morokrembangan and served as the headquarters for Captain P. J. Hendrikse, who commanded all MLD and Allied reconnaissance operations in that part of the archipelago. MVK Halong consisted of three large hangars, three underground fuel tanks, workshops and a number of barracks that were still under construction when the island fell to the Japanese in January 1942. The island was also a support base for the KM with powerful radio facilities and naval base that in reality served as little more than a staging point for Dutch submarines.
A naval air station for the MLD since the 1920s, MVK Tarakan was modernized in 1940 and capable of supporting two GVTs. Improvements included the construction of large barracks for flight and ground crews, an electric plant, maintenance workshops and two underground aviation fuel storage tanks with a capacity of 220,000 gallons each. In late 1941, it received a small floating aircraft dock and expanded facilities that let it carry out simple aircraft repairs. But despite its status as a major support hub for MLD operations in the northern NEI, Tarakan in fact remained little more than a well-equipped support base.
The Dorniers of GVT.4 moored in Bima Harbor, March 1939 (photograph courtesy of Nol Baarschers).
There were also three lesser-developed support bases. The first was Kalkas, which had been established on the southeastern edge of Lake Tondano on Northern Celebes in October 1941. It featured a small workshop, and two squadrons could operate from the base. The ML was supposed to have provided air cover for the base from Kalawiran Airfield, situated some three and a half miles southwest of Lake Tondano near the town of Langoan. However, it appears that a shortage of fighter aircraft meant that none were ever deployed to the airfield during the East Indies campaign. This would contribute to the tragic losses suffered by two MLD squadrons at Kalkas on December 26, 1941.
At the same time, Balikpapan on the east coast of Borneo, and Pontianak in southern Borneo, allowed MLD patrols to effectively patrol the South China Sea and Makassar Strait. Of the two, Balikpapan was the oldest. Although officially rated as a support base, it could support the operations of two squadrons and was able to provide them with routine maintenance and other repairs thanks to a floating dock that been towed to the port from Java between September and December 1939. Pontianak had become operational only in 1940, but like Kalkas on Lake Tondano, it featured a small workshop that allowed minor aircraft repairs and maintenance.
In addition, the MLD had 51 remote bases scattered throughout the NEI.15 Usually situated near isolated settlements, they included the Riouw Archipelago, the Talaud Islands, Ternate and Morotai in the Moluccas Islands and Sorong, New Guinea. The MLD also reached a prewar agreement with the British government to establish a seaplane base on Christmas Island, 300 miles south of Java in the Indian Ocean. Although fully stocked, the MLD never had adequate strength to use this base during the East Indies campaign.
MLD pilots also had another 153 auxiliary bases on their charts.16 Of these, 43 were undeveloped staging points for the most part. Although rare, some had skeleton ground crews and radio facilities that let them communicate with Morokrembangan. However, all contained hidden fuel and ordnance dumps, providing adequate stopover points for refueling, repairs and rest for the aircrews. The remainder were little more than primitive jungle campsites situated on secluded rivers and lakes that had been established for the dispersal of aircraft if required.
The MLD could also count on a number of so-called “Guaranteed Depots” to help maintain its air operations in remote parts of the archipelago. These were supply depots strategically located at various civilian oil company facilities, ports and seaplane bases. Stocked and maintained in conjunction with civilian oil companies, they contained fuel, oil and other supplies that MLD aircraft would require in order to maintain air operations.
All the seaplane bases were serviced in one way or another by a wide variety of small boats. These included fast motorboats for personnel transport, boats for refueling seaplanes in the harbor, specialized ordnance boats for “bombing up” planes and “crash boats” to rescue survivors or to take off wounded. At Morokrembangan, the MLD operated small harbor boats, which resembled miniature tugboats. These maneuverable boats had a cockpit forward with a towing bit placed amidships. This design allowed the coxswain to put the seaplane in tow wherever he wanted.17 Although few of these boats were standardized, no base could effectively function without them, and their destruction seriously limited the efficiency of an MLD base.
The lifeline provided by these forward bases was possible thanks to large supplies of fuel, oil and ordnance stocked before the war and supporting aircraft tenders of the Governments Marine. The Governments Marine (GM) was a civilian naval force similar in organization and function to the United States Coast Guard. As a state police force, its peacetime duties included police work, customs and drug interdiction, although in times of war, it came under the operational control of the KM.
Militarized in September 1939, GM patrol boats and auxiliaries were put under the operational command of the East Indies Squadron. Seven of the larger patrol boats—Arend, Bellatrix, Fazant, Merel, Poolster, Reiger and Valk—were converted and assigned to the MLD for use as seaplane tenders. Carrying aviation fuel, oil, spare parts, supplies, ammunition and powerful communications equipment, they provided an invaluable network of mobile support bases that allowed a GVT to simply relocate when threatened. It appears that a small number of single-engine Fokker floatplanes were also attached to Arend and Valk in a utility role, and the two ships were equipped to operate a single aircraft as part of their normal complement.
This broad network of seaplane bases let the MLD maintain a high degree of operational efficiency and mobility both prewar and throughout the East Indies campaign. It also let the Dutch keep a wide eye on what the Japanese were doing as they moved toward Java. The militarized seaplanes of KNILM, which used its prewar civilian hub facilities, patrolled those areas of the NEI that the MLD could not cover.
Fazant was one of seven Governments Marine patrol boats converted for use as MLD seaplane tenders in 1939–40 (photograph courtesy of Jan Klootwijk).
Japanese strategy centered on neutralizing these bases, and it proved effective. Throughout the campaign, the GVTs lived a nomadic existence, being harried from base to base. One squadron operated from 5 different bases in 15 days. Flying 16- to 18-hour missions for days on end added to the strain for Dutch air crews. Although the MLD tried to rotate squadrons out of the line, this was not always possible. As the war converged on Java, there soon were no safe places left for them to hide.
A primary reason for the overwhelming success of Japanese air strikes on Java was clearly the Allies’ lack of fighter aircraft. Another was the weak state of Dutch AA defenses across the board. Although their weapons were of excellent manufacture and quality in general, there were simply too few available to make much of an impact. The KNIL’s decision to parcel them out in penny packets in order to provide important facilities with some semblance of air defense only served to further dilute their effectiveness.
In December 1941 the KNIL, which was responsible for AA defenses throughout the East Indies, could count on the services of only four heavy AA batteries. These were composed of one 105mm and three 80mm AA batteries. They were supported by 104 Bofors 40mm AA guns that had been acquired from Sweden between December 1936 and December 1939. The KNIL had also ordered a substantial number of Rheinmetal 20mm light AA cannon from Germany, although only small numbers of these weapons reached the NEI prior to May 1940. The Swedish firm of Bofors was the primary manufacturer and distributor of the heavy pieces, although the acquisition of 75mm AA guns from this firm had also been disrupted by the war in Europe.
Because of the importance of these targets, the heaviest AA weapons were concentrated at Soerabaja, Batavia and Bandoeng, capital of the East Indies government and traditional headquarters of the Dutch military’s high command. As the seat of power, Bandoeng had 20 80mm AA guns to defend it.18 At the same time, Soerabaja had eight 80mm batteries deployed throughout the city and port.19 The civilian and naval ports at Tandjoeng Priok were allocated a total of four 80mm and six 40mm guns.20 The naval air station was defended by four 40mm AA.21
The remaining weapons were parceled out in small numbers. As a primary airfield on east Java, Perak was allocated four 105mm and four 40mm AA guns.22 Being in such close proximity to the airfield, Morokrembangan benefited from their firepower as well, although the seaplane base had only a single battery of two 20mm cannons for its own defense.23 Air defenses at all of these facilities were typically supplemented by 7.7mm and 12.7mm machine guns, although they were virtually useless against anything other than strafing fighters. In most cases, the latter were the only air defense at larger MLD support bases in the outlaying territories.
The Dutch fully realized this deficiency as early as June 14, 1940, when the NPC presented a list of needed armaments to the United States Treasury Department’s Procurement Division. No longer able to procure additional weapons from its traditional European suppliers, the KNIL, which was responsible for AA defenses throughout the NEI, requested permission to purchase substantial numbers of AA guns with ammunition, rangefinders, searchlights and related equipment from either the United States Army or American arms factories. This equipment included:
In response to this and other urgent requests from the NEI government, the United States Army dispatched a military mission to Java to review Dutch military defenses and ascertain their actual military needs firsthand. As might be expected, the Dutch cooperated fully with the members of the mission and provided a detailed look into the state of their defenses and provided a comprehensive list of their requirements. In the following chart, it is interesting to note that the KNIL’s AA requirements increased dramatically from their initial needs just two months earlier.
As is clearly seen, the Dutch needs for their AA defenses alone were massive, and they had little time to rebuild or strengthen them. A great deal of this deficiency can be attributed to the United States’ early refusal to sell weapons to the Dutch out of fear that the East Indies government would fold under Japanese pressure and become little more than a quasi-protectorate within the Japanese Empire. So although the United States did agree to supply AA weapons to the KNIL, it did so too late for most of the orders to be filled. So whether through human delay or unavailability of the requested equipment, the Dutch in December 1941 faced a crippling shortage of weapons and equipment that time and again would lead to tragic losses for the MLD.
Table 2: AA Weapons Requested by the KNIL, June 194024
1 battery (four 90mm AA guns): to be delivered with fire-control apparatus, electric-transmission system and 13-foot range finder, four spare barrel liners and 38,040 high-explosive shells.
13 batteries (four 80mm AA guns each): to be delivered with 21 fire-control directors, each with a fire-control apparatus, electric-transmission system and 13-foot range finder. They would also come with two spare guns, a small number of spare barrel liners and munitions cases and 37,440 high-explosive shells.
• 5 batteries (three Bofors 40mm AA guns each): to be delivered with 15 telephones. 15- × 7-foot rangefinders. 1,500 cartridge holders and 30,000 high-explosive shells.
• 17 batteries × (two Bofors 40mm AA guns each): to be delivered with 68 spare barrel liners, 20 fire-control systems, 3,400 cartridge holders and 68,000 high-explosive shells.
• 32 batteries (two Bofors 40mm AA guns each): to be delivered with 128 spare barrel liners, 32 telephones, 32 7-foot rangefinders, 6,400 cartridge holders and 128,000 high-explosive shells.
• 16 batteries (two Hispano-Suiza 20mm AA guns each): to be delivered with 64 spare barrel liners. 130- × 3-foot rangefinders, 384,000 high-explosive shells and 76,800 armor-piercing shells.
• In the event that Bofors 40mm weapons were unavailable, the Dutch also indicated a willingness to accept 37mm AA weapons with simplified fire control systems.
Table 3: Dutch AA Requirements, August 194025
Equipment: 90mm Mobile Mount: Total Needs: 60, On Hand: —, Number Requested: 60, Remarks: Urgently requested for defense of naval bases important military facilities 18 and use by KNIL.
—Extra gun barrels: Total Needs: 60, On Hand: —, Number Requested: 60
—Fire-control sets: Total Needs: 15, On Hand:—, Number Requested: 15
—13-foot rangefinders: Total Needs: 18, On Hand: —, Number Requested: 18
—HE shells with mechanical fuses: Total Needs: 41,500, On Hand: —, Number Requested: 41,500
Equipment: 80mm Fixed Mount: Total Needs: 28, On Hand: 28, Number Requested: —, Remarks: For defense of naval bases, and important military facilities; rangefinders and fire control sets urgently needed.
—13-foot rangefinders: Total Needs: 8, On Hand: —, Number Requested: 8
—Fire-control sets: Total Needs: 9, On Hand: 2, Number Requested: 7
Equipment: 40mm Mobile Mount: Total Needs: 140, On Hand: 40, Number Requested: 100
—Complete fire-control set: Total Needs: 70, On Hand: —, Number Requested: 70, Remarks: Urgently requested for defense of naval bases, and important military facilities.
—7-foot rangefinders: Total Needs: 77, On Hand: 32, Number Requested: 45
—3-foot stereoscopic equipment for observing tracer fire
—Ammunition (tracer): Total Needs: 680,000, On Hand: 80,000, Number Requested: 600,000
Equipment: 20mm Mobile Mount
—1-watt rangefinders
(stereoscopic picture type): Total Needs: 160, On Hand: 30, Number Requested: 130, Remarks: Urgently needed
—3-foot stereoscopic equipment, Total Needs: 80, On Hand: —, Number Requested: 80
for observing tracer fire: Total Needs: 80
—Ammunition
Equipment: HE/Tracer: Total Needs: 1,200,000, On Hand: 200,000, Number Requested: 1,000,000, Remarks: 70,000 ordered in USA; delivery expected August 1941
Equipment: Armor Piercing: Total Needs: 400,000, On Hand:—, Number Requested: 400,000
Nonetheless, the Dutch AA forces did receive a small number of reinforcements in early 1942. In the first week of February 1942, several British AA units that had been evacuated from Singapore reinforced the KNIL batteries. These units included the 21st Light Anti-Aircraft Regiment with nine 40mm AA guns and the 77th Heavy Anti-Aircraft Regiment with nine 3.7” weapons. Unfortunately, the latter were hampered by a shortage of ammunition after the merchant ship Derrymore was sunk during the evacuation of Singapore while carrying a cargo of 3.7-inch shells.
The British guns also arrived on Java with the only radar set in the East Indies. This equipment was set up on the island of Madoera, just north of the ME. However, the British did not fully trust the Dutch or their Indonesian troops and did not allow them to come near the installation. Nor, it appears, were they willing share information on how it functioned, lest it fall into the hands of the Japanese through Indonesian spies. Although the radar set was not functional during the first Japanese raid on Java, it remained on-line throughout the rest of the campaign.
The MLD went on its first war footing when Italy invaded Albania on April 7, 1939. Although there was little threat of the conflict spilling over into the East Indies, Captain K.W.F.M. Doorman, commander of the MLD forces in the NEI, ordered two squadrons at Morokrembangan to bases in the Makassar Strait and Riouw Archipelago, where they initiated neutrality patrols on April 13. The squadron operating in the Riouw Islands was supported by the seaplane tender Hr.Ms. Bellatrix, which in turn, was under the command of the gunboat Hr.Ms. Flores.
On September 8 of that year, the GM patrol vessels Sirius, Fazant and Reiger were ordered into the ME, where they were converted into MLD seaplane tenders. Three weeks later they were put under the operational control of the ME naval commander and MLD reconnaissance commander of the eastern East Indies at MVK Halong on Ambon. They joined Bellatrix, Arend and Valk, which had been militarized and converted for MLD service several months earlier. In this capacity, all of the tenders transported fuel, munitions and supplies, in addition to carrying out minor aircraft repairs and changing out motors during overhauls.
Immediately prior to the outbreak of widespread war in Europe, Captain Doorman received orders to maintain no fewer than eight GVTs in active service at all times. At least two of the squadrons were assigned to the East Indies Squadron in a reconnaissance capacity. Two more were based in the Moluccas Archipelago (operating from Ambon), with single squadrons based in the Riouw Islands and at Tandjoeng Priok, Tarakan and Balikpapan. Although most of these aircraft were Do. 15s or Do. 24s, the last two squadrons flew Fokker T.IVs.
When Germany invaded Poland in September 1939, the MLD had 78 large seaplanes in service with its East Indies squadron. These included 26 Dornier Do. 24, 19 Dornier Do. 15, 17 Fokker T.IVa, nine Fokker C.XI-W and seven Fokker C.VII-W aircraft, the last seven dating from the mid to late 1920s.26 Front-line strength of the fleet air arm in the NEI consisted of nine GVTs operating a mixture of modern Do. 24s, which were slowly replacing the obsolescent T.IVs.
The Dutch planes immediately began flying neutrality patrols over the East Indies to prevent the war from creeping into their territory. Most of the flights were around Sabang in the Malacca Strait, over the Soenda Strait and along the west coast of Sumatra. GVT.2 (X-11, X-12 and X-13) also began flights over the southern Makassar Strait and South China Sea, while GVT.4 (X-19, X-20 and X-2) set up operations at Ambon and initiated regular patrols over the eastern half of the East Indies.27 These patrols were soon intensified as the combatants began operating in and around NEI waters.
Following the outbreak of war, 19 German merchant ships sought refuge in NEI waters. As Holland and the NEI were still neutral, all were interned.28 However, British forces kept close tabs on them, leading to several violations of Dutch territory. The first occurred on September 6 when a seaplane from a British cruiser attacked the German merchant ship Franken, and on at least two other occasions Royal Navy ships illegally entered Dutch waters. Then in April 1940 a Dutch aircraft fired warning shots against another seaplane operating from an RN armed merchant cruiser near Makassar. The British plane had entered Dutch territory to reconnoiter the German merchant ship Scheer, which lay interned in the harbor.29
Seven months later, on November 16, the German battleship Graf Spee stopped the Dutch merchant ship Mapia in the Indian Ocean near Durban, South Africa, and inquired about her cargo. Although the German captain let the neutral freighter go, it was feared that the raider was moving toward the East Indies. To ensure Dutch neutrality, the MLD began a series of patrols along the sea-lanes around Sabang harbor in Northern Sumatra. Although these flights were eventually discontinued, renewed reports of German armed merchant cruiser activity would again spark a week of intense reconnaissance patrols between Dutch New Guinea and the island of Celebes in early 1941. By that time though, Germany and the Netherlands were at war. As a result, the Dutch airmen actively sought out the German raiders, but without success.
On December 13, Bellatrix reported an unidentified Japanese tanker entering Dutch waters through the Lombok Strait. Even at this early stage, the Dutch were fearful and uncertain of Japanese intentions toward the East Indies and took steps to keep the tanker under observation. KM HQ on Java immediately ordered Captain Doorman to carry out reconnaissance patrols over the area using aircraft operating from southern Java and the Lesser Soenda Islands. However, before the patrols could be organized, the Japanese ship disappeared and was not seen again.
In response to Japan’s continued war on the Chinese mainland, the United States banned all copper and brass exports to the Japanese in January 1941. As an island nation with few natural resources of its own, these items were absolutely vital if Japan was to continue its war in China. Without them, its war effort would slowly grind to a halt. The final blow came when the Dutch followed the American lead and stopped all oil exports from the East Indies. With its vital resources cut off, and surrounded by what it regarded as enemies, Japan made ready to fight.
Although Japan had openly coveted control of the East Indies since the First World War, it had been reluctant to act while the Dutch homeland remained unoccupied. However, with many of Holland’s strongest allies under Nazi occupation, and the remainder fighting for their existence, Japanese nationalists felt strong enough to act in early April 1940 when the IJN was put on “Increased Readiness”30 in preparation for an invasion of the East Indies beginning May 1, 1940. At the same time, senior fleet officers were ordered to prepare for war against England and the United States, as the Japanese military believed that neither country would idly stand by while Japan blatantly committed such an aggressive act of war.31
Beginning the first week of April 1940, the Dutch received a series of reports that warned of the Japanese plans. The bulk of this information came from a sympathetic high-ranking German officer inside the Abwehr;32 he also warned of the pending German invasion of Holland,33 which was confirmed by similar signals from the Vatican as well. In response the KM assembled the East Indies Squadron off the coast of Borneo, and the MLD intensified reconnaissance flights over the South China Sea, Makassar Strait and Moluccas. Tensions rose even higher when it was learned that a large concentration of Japanese ships had assembled at the island of Formosa, which was assumed to be the departure point for any invasion of Dutch territory.
It is unknown whether a formal invasion plan was ever drawn up, but from records found in Kriegsmarine archives, it appears that Japan planned a lightning strike against the East Indies in conjunction with the pending German invasion of Holland. As their final decision rested on German invasion plans, the Japanese pushed the Germans for specifics on their invasion plans throughout the first two weeks of April. However, on April 17 Vice-Admiral Nobutake Kondo, the IJN’s Deputy Chief of Staff, ordered his forces to stand down as the Japan Cabinet still wanted to avoid war with the United States and Great Britain by pursuing a policy of negotiation.34
The Japanese operated some 500 civilian fishing and pearling boats throughout the NEI, secretly mapping installations and taking harbor soundings (photograph courtesy of National Archives of Australia).
So instead of an overt invasion, the IJN took steps to intensify covert intelligence operations throughout the East Indies. A large fleet of approximately 500 Japanese fishing boats—manned by some 4,000 civilians, reservists and active-duty personnel—was assigned to these operations.35 To support this fleet, the Japanese set up entire fishing communities and fisheries throughout the NEI, which allowed their ships to move at will. In some instances, Japanese submarines resupplied them.
As a result, the fishing boats were able to move freely. In the process, they often flagrantly violated Dutch territorial waters and fishery regulations to “fish” and dive for pearls near important military installations. When stopped and searched, many were often found with sophisticated sounding equipment, well-detailed charts of various harbors throughout the East Indies and powerful radio equipment capable of transmitting all the way to Japan.
In areas where Dutch rule was weak, the crews of these fishing boats often landed on smaller islands to bully the civilians and steal food. They also engaged in opium trafficking, shipments of which were relayed to them by other Japanese ships outside Dutch territorial waters. Powerful crime syndicates with top military ties undoubtedly operated these operations, as this type of activity was also rampant in the occupied areas of mainland China and Manchuria.36
The sheer size of this fleet and its movements caused tremendous intelligence concerns for the Dutch fleet. To help police their movements, a naval squadron including the light cruiser De Ruyter was deployed off Celebes, and her shipboard seaplanes were extensively used to locate and monitor the Japanese fishing boats. At the same time, an MLD group was sent to the Lesser Soenda Islands archipelago, while submarine divisions were deployed to Ambon and the port of Bima on Soembawa Island. But even with the help of the Governments Marine and intensified air patrols by the ML, there was still much space left for the Japanese to operate.
In February 1941 a large Japanese naval task force assembled off northern Indochina. At the same time, the Imperial Japanese Army began stockpiling war supplies throughout Indochina and Formosa. Alarmed by this build-up, Admiral Helfrich ordered all Dutch ships to concentrate in the southern half of the South China Sea. He also ordered all warships under repair or in overhaul to be ready to put to sea within 24 hours of receiving orders.37
On February 11, Dutch merchant ships in Chinese and Japanese waters were ordered to head south for safer waters. That same day, Admiral Helfrich also closed all Dutch harbors to Japanese shipping. The Dutch clearly expected a Japanese invasion in the immediate future. They believed there would be a direct attack on Java itself, and all available warships concentrated at Soekadana Bay on Western Borneo to intercept such a thrust. Here, shallow water prevented Japanese submarine attacks, and the MLD carried out a series of intensive, long-range patrols to the north; cruiser floatplanes searched the immediate area.
However, the anticipated attack never materialized, and eventually the Dutch state of readiness lapsed as it became clear that Japanese attention for the time being was focused on Indochina. Tensions, which were already high following the oil embargo, had been taken almost to the breaking point. At the same time, the Japanese were now well aware that the Dutch were prepared to resist any invasion of the NEI. This led to the start of an intense cold war in which both sides knew there was no turning back a full nine months before Pearl Harbor.
Hr. Ms. De Ruyter launches one of her Fokker C.XI-W floatplanes (photograph courtesy of Institute for Maritime History).
These activities by the Japanese finally convinced the Dutch to openly participate in joint defensive planning sessions with the Australians and British. They had previously not done so to avoid provoking the Japanese. At one of these joint meetings, a RAF staff officer from Singapore requested, and was granted, permission to tour various Dutch bases throughout the East Indies with an eye toward Commonwealth forces using them in the event of war. The Dornier X-9 then spent a week ferrying him and an ML officer between the ME and the bases at Ambon, Lake Tondano, Tarakan and Balikpapan before returning to Soerabaja.
As the Allies solidified their defensive plans, the Dutch and Japanese engaged in a number of provocative incidents. On May 6, a Do. 24 sighted a suspicious motorboat without a national flag operating in the Dutch-owned Riouw Archipelago, just south of Singapore. As the seaplane circled, its crew identified the boat as being Japanese and repeatedly issued orders for it to leave Dutch territorial waters, all of which were ignored. In an effort to stop and search the ship, the X-boat pilot then attempted to land nearby. As he did the Japanese skipper attempted to ram the seaplane, leading Dutch gunners to fire several rounds across the Japanese ship’s bow.38
Natives pose in front of X-9 at an unknown MLD seaplane base, most likely in New Guinea or Borneo (photograph courtesy of Institute for Maritime History).
Some time later, a Japanese officer sent a highly fictionalized account of this encounter to his superiors in Tokyo. His version not only claimed that the Dutch had deliberately fired on the fishing boat first, but also that British troops had also landed on Java as part of a plan to take the NEI into British custody as a protectorate.39 Although the report failed to induce the war he sought, this officer helped to further intensify the Dutch-Japanese cold war.
In another incident40 off western Borneo, the crew of a Japanese fishing vessel lined the railing of their vessel and challenged an MLD seaplane to fire on them. They clearly hoped to provoke an international incident, but the plane’s commander refused to play along. Nonetheless, the Japanese political pressure brought about by these actions was tremendous. Anxious to avoid inflaming the situation, the Dutch government agreed to use its seaplanes only for reconnaissance and to cease the practice of stopping and searching Japanese fishing boats at sea. Almost immediately, the fishing boat crews were apparently ordered to routinely ignore orders from MLD aircraft to leave Dutch territorial waters when discovered.41
Later that month Dutch planes sighted the Japanese cargo ship Zuyo Maru in the Halmahera Sea with a suspicious deck cargo. However, no ships were close enough to intercept, and contact was lost. On the 22nd, however, the Governments Marine patrol boat Arend stopped and boarded the Asahi Maru in Dutch waters off New Guinea. But nothing was found, and Arend was forced to let the ship and her laughing master go about their business.
As tensions mounted between the Dutch and Japanese, the NEI government stepped up military relations with its American, Australian and British counterparts. From May 15 to 20, three MLD Do. 24s flew from Morokrembangan to Darwin and back via Koepang in an exercise designed to strengthen military ties between the two nations. Although the Dutch had participated in a series of joint defense planning sessions with the Americans, Australians and British at Manila, Singapore and Batavia in 1940 and 1941, they had up to this point refrained from overt military cooperation.
These planning sessions resulted in the creation of a series of classified inter-Allied codes for Anglo–Dutch–United States Radio Communications. They were issued to Allied land and seaplane flight crews throughout the Far East in May 1941 and included standardized operating procedures, radio call signs and a detailed list of reconnaissance signals. An Anglo–Dutch–United States table of lettered coordinates was also distributed in August 1941.
The Dutch then participated in a two-day operation between July 23 and 25 with American and British aircraft. Each nation executed a series of reconnaissance flights throughout its respective operational areas, which had been previously established at the American-Dutch-British talks at Singapore in 1941. Although the primary goal of the operation was to familiarize the aircrews with the above protocols, it also proved helpful in helping determine logistics and equipment needs at various allied air bases throughout the Far East. As a result of this operation, a RAF seaplane base was established at Sabang harbor on Malaya’s western coast.
Meanwhile, Japanese fishing boats continued intensify their espionage operations throughout the NEI. In response to a rash of intrusions into the Dutch territorial waters, Admiral Helfrich ordered GVT.7 to the MLD base at Pontianak, Borneo, with the tender Poolster on September 24. From there, the squadron flew reconnaissance patrols in the area of the Natoena, Anambas and Tambelan Islands until transferred to Tarakan on December 6.
On September 28 an unidentified X-boat reported a suspicious ship in the Ceram Sea. Believing it to be a Japanese spy ship trespassing in Dutch waters, the KM sent out two destroyers to investigate. However, by the time they reached the area, the vessel had disappeared, and they were recalled.
Numerous operations such as these continued until November 23, 1941, when the Royal Australian Navy (RAN) requested Dutch help in locating one of its cruisers, which had gone missing while en route from Singapore to Fremantle, Australia. At the time, no one knew the German merchant cruiser Kormoran had sunk HMAS Sydney on the 19th. Although there were no survivors from Sydney, German sailors later testified that the Australian captain had let himself be drawn within range of the merchant cruiser’s guns and torpedo tubes. In an action lasting approximately one hour, both ships received mortal damage and drifted out of sight of the other before sinking.
Sydney went down without a word and was declared overdue when she failed to enter port. However, a full-scale search-and-rescue mission began in earnest only when merchant ships started to rescue survivors from Kormoran. Although Sydney failed to answer repeated signals, it was hoped that her transmitter had been damaged and she was making for a port in the NEI.
In response to a RAN request for immediate assistance, Admiral Helfrich deployed the light cruiser Tromp to the Soenda Strait with orders to follow Sydney’s last known course. At the same time, he ordered MLD units from Morokrembangan, Tandjoeng Priok and Tjilatjap to sweep the Indian Ocean between Java and Christmas Island. Despite intensive sweeps along all possible paths of the Australian ship and heavy damage to Tromp’s C.XI-W floatplane during the operation, they found nothing, and all units stood down several days later. To this day the exact cause of Sydney’s loss remains unknown.
Between September 1939 and December 1941, MLD aircraft flew more than 3 million miles in an effort to preserve Dutch neutrality and keep Japanese espionage activities under control. In the process, they maintained a regular Dutch air presence throughout a territory the size of Western Europe and helped secure a border perimeter totaling some 7,800 miles.42 Perhaps more important, they also provided raw flight crews and reservists with invaluable operational experience under wartime conditions, thus preparing for what they would soon encounter.
But despite being successful for the most part, these neutrality patrols inflicted tremendous wear and tear on the MLD’s aircraft and equipment. And while the MLD had the facilities, personnel and expertise to maintain regular overhauls during peacetime operations, a shortage of certain spares and engines made the German-built Dorniers and older Fokkers increasingly difficult to maintain. As a result, the number of mechanical accidents and aircraft losses rose accordingly with the outbreak of war as the MLD struggled to maintain its cohesion in the face of savage Japanese air attacks that would grow more intense with each passing month.