Specialist officers knew the latest equipment. Norton Griffiths spent much of his prodigious energy sourcing the best pumps, boring equipment and much else and making sure that they were provided without delay. Füsslein complained that the British had superior equipment, for example pumps to dewater the deep levels, and that he could not obtain similar equipment from Germany. Trower, who was appointed in command of 252 Company, was the Paris representative of the Ingersoll Rand Company and quickly obtained compressors, which for use in hard chalk. All adopted drills powered by generator or compressor, which were used especially when working some distance away from the enemy and in conjunction with borehole blasting. Blasting was disliked by some British officers because it was inevitably heard by the other side and alerted them to the work. The French and British also experimented with types of forcing jacks, whereby pipes were driven along beneath the surface of the ground, which were used to blow charges. These appeared to offer a means of placing explosive charges against the enemy front line, to blow a breach into a trench and also to blow a communication trench across no man’s land. The British did not have success with them at St Eloi on 27 March 1916, where a Barrett Forcing Jack was supposed to blow a ready-made communication trench to the British Crater No.1, but succeeded only in blowing up a section of the British front line.⁹ The main problem with forcing jacks was that they could only be used effectively through soft ground. The Sentinel Pipe Pusher was developed for the same purpose by the British but attempts to use it on the Somme, where flints would deflect the head of the head of the pipe and drive it off course, met with little success. It was found that borers were more reliable than jacks and the most effective British, equipment was brought by the Australian Mining Corps. The invention of Captain Stanley Hunter of the Victorian State Mines Department, the ‘Wombat’, could drill a hole of up to 6^1/2in in diameter up to 200ft at about 3–4ft an hour through chalk. Communication trenches blown using the Wombat were used at Vimy on 9 April 1917.