Sue joined the quaint members of the indexing team the following Friday at Bremham vestry. Soon she got into the swing of the action, although she did find that it was an effort to maintain the required concentration. How these elderly old dears managed was a wonder to her. Everyone worked well with each other. It was a team effort.
During her second visit, a week later, Peter mentioned that he would be going up to London on the following Tuesday, which delighted her. Although she had been trying to busy herself with other things, such as the indexing work, her own research in waiting was never far from her thoughts.
Tuesday arrived. Sue was, as usual, ready early and had time to look through the information that she had so far amassed. Even at this early stage, she was conscious of the difficulties she would encounter in dealing with the expanding list of direct ancestors, as she moved backwards through the generations. Soon, even if her searches were only partially successful, the amount of information could become unmanageable. Clearly she would need to be selective. The problem could resolve itself naturally as some of her family surnames became difficult to trace. This had already begun, insofar as she had only managed to trace two of the four marriages of her great grandparents. She decided to defer any decision until later. Her immediate task was to search for the birth details of at least some of her great grandparents and so, she would once again be amongst the birth indexes at Somerset House.
Peter arrived. He had one passenger with him, a man unknown to Sue, who she learned was a member of the local family history group. They were both intending to visit the Newspaper reference library. Sue travelled from Hammersmith alone, which pleased her, as she could be flexible about lunch.
She entered into the search routine with the air of a regular, which of course, she now was. She had details from the two marriage certificates which, in addition to the ages of her great grandparents at the time of their marriage, included the names and occupations of their fathers. She began her search through the birth indexes around the likely birth dates, based upon their age at the time of their marriage, although she had no idea of their places of birth. She was rewarded with promising results for two of her great grandfathers, finding birth details which seemed appropriate. The first was born in Woolpit in Suffolk and the other in Kensington. Her first real dilemma arose with her great grandmother Potten, when she found two Caroline Pottens in the index born in 1846, which was the likely birth year she had deduced from her great grandmother’s marriage certificate. She thought this perverse, as it was an unusual surname and there were no other Caroline Pottens listed for several years either side of this date. Both were registered in Brighton. She decided to apply for both certificates and then later attempt to determine which of the two was her great grandmother.
On the journey home, Sue mentioned her problem to her more experienced fellow travellers. They agreed that she had done the sensible thing in applying for both certificates. She should be able to confirm which certificate was her great grandmother’s, by checking the name of her father. She already knew, from Caroline’s marriage certificate, that the one she sought was named Thomas, who was a carpenter.
Back in Wiltshire, she was pleased to find everyone at home. The girls and the Potter kids were, making the most of the lighter evenings, playing an improvised version of volley ball using a makeshift net strung across the front lawn. Dave, having returned from his run, was in the kitchen making a start on preparing the meal. It seemed that he wanted to eat early as he had work to do. When hadn’t he?
A few days later the four certificates which Sue had ordered arrived. She was pleased to find that her great grandfather, Thomas Boughton was born in 1842 in Woolpit, Suffolk, and that his father’s name was indeed James. She had similar details recorded on the next certificate, which was for another great grandfather, James Loomes, who was born in Kensington in 1848. His father was John, a house painter. So far so good. Next she turned to the first of the certificates for Caroline Potten. Of course, she knew from the earlier marriage certificate, that Caroline’s father was named Thomas and he was a carpenter. She was delighted when she found that this was the case for this first Caroline, who was born in Brighton in May 1846. Caroline’s mother’s name was Elizabeth Baker. The address was given as number forty one, Upper North Street.
From this information Sue could see the next part of her research, regarding these three families, would entail checking the census returns for 1851 as the next generation, moving backwards, would have been born, perhaps even married, before civil registration had been instituted in 1837. As she now had the addresses of two of her great grandfathers, at least at the time of their birth, she could start at those locations in her census search, hoping that they hadn’t moved home. She imagined that, as Woolpit was likely to be a small village, the Boughton family should be easy to locate. She decided to start there and then move on to Kensington to seek out the Loomes. As for her great grandmother Caroline, she would check number forty one Upper North Street.
She put her certificates into her wallet folder and, almost as an afterthought, checked the certificate for the other Caroline Potten out of interest. She read through this with an increasing sense of shock:
Caroline Potten b. 7th Nov 1846, father Thomas, mother Elizabeth Worth, father’s profession – carpenter.
She couldn’t believe it, same name, same place and year of birth, both fathers were carpenters named Thomas and both mothers were named Elizabeth. This second Caroline was born in Chichester Street. She was stunned. She had not resolved her difficulty and still had no way of knowing which of the two was correct. She could only hope that Peter might be able to advise her.
During a break from the laborious indexing work at St. John’s, Peter and Sue sat a little apart from the ‘Dickensians’ – as Sue thought of them – and Peter went through her Potten birth certificates.
“Hmm! The road not taken it seems,” was his comment.
“Pardon me,” asked Sue.
“Oh! Sorry. Robert Frost. It’s a poem,” Peter explained.
“But will his poem help me?”
“No, it’s just a bad habit of mine, I’m afraid. I can’t suggest anything positive just now, nothing that would definitely resolve your dilemma. However,” Peter thought for a moment, “I believe that for the present you should regard them both as your great grandmother. It could be that they are descended from a common ancestor, they could be cousins. It’s quite an unusual surname after all. If they were closely related, then you could construct a family tree for both and carry on back from there, possibly finding them joining up to a common ancestor. It may be that later, when you’ve used other sources of reference, you will know which is correct.” Once again she couldn’t wait to be on her travels.
*
Dave was back on the Winford road again. He was intending to carry out an inspection of his on-site specimens. Bunsen was with him, providing a constant stream of lively chatter. It seemed that almost any incident or any object that they passed could spur him into some tale or anecdote which stirred in that buzzing brain of his. He really was, Dave thought, the absolute stereotype of the mad professor that many people call to mind when thinking of scientists. In amongst his observations Bunsen did include, for Dave’s benefit, a potted history of boiler water chemistry and how this had changed over recent years. The two basic strategies to prevent corrosion of the metal components within the water/steam circuit were the removal of oxygen and the maintenance of alkaline conditions, within the circuit. During the early period of operation at Winford, the boiler water had been dosed with sodium hydroxide, but in recent times, the chemical hydrazine was mainly used with sodium hydroxide only as an occasional back up.
Bunsen explained that today he was planning to check the steam quality readings. He would also collect the first few weeks of completed instrument charts and recalibrate his reference standards. In order to save time, Dave had arranged to have the steam to his test vessel turned off a couple of hours before he was due to arrive, so that he could get access to his samples immediately.
After signing in they changed into their overalls. Whilst Bunsen went to meet the Station Chemist, whistling tunelessly along the corridor, Dave made his way to the turbine hall to open his test vessel. He was pleased to see that the pre-cracked specimens on the top tray had acquired an even, shiny, black surface coating, similar to that found on LP turbine discs after service. He made a mental note to ask Joe if this was also the case with his laboratory steam rig specimens in Nuneaton. After removing the pre-cracked specimens from the vessel, Dave inspected each one for signs of crack extension. He was only using a visual check this time and not x-ray, as he didn’t want to lose exposure time in the test rig, which would be the case if he wanted to take them away for more accurate measurement. It was early days and the extent of extra crack growth, if any, would be very small. He had a magnifying glass with its own light source which he used to aid his inspection – and yes, yes – he was sure. He could just detect the smallest suggestion of growth on several of the specimens. Next, he examined his own extra samples, those without pre-existing cracks, and was pleased to find that they were also oxide coated along the whole of their test length. Dave could not detect any surface features that would suggest cracking or even pitting, but he accepted that this would be unlikely using normal visual methods alone. After making his notes, he replaced the specimens into the test vessel, closing the lid securely. He returned the rig to service before checking on Bunsen’s progress. Following a canteen lunch, during which they chatted with station engineers, Dave returned to the turbine hall to make a note of the temperature and pressure readings in the test chamber, whilst Bunsen clambered up the scaffolding to inspect his instruments.
They managed to get away from the station early, which suited Dave as he wanted to get back to work in time to make a start on his contribution for the forthcoming sub-committee meeting. How quickly these seemed to come around.
Back at his desk he phoned Pauline to check on a couple of agenda items and he took the opportunity to let her know that, although he would not be staying overnight this time, he trusted that their dinner date would still be valid when he could make the arrangements. Pauline assured him that, although she hoped he wouldn’t feel that she was being too forward, she was intending to hold him to it. Dave hung up and sat back in his chair with the smile of the middle-aged man who apparently hadn’t lost all his charisma.
The meeting day arrived and the members assembled. A routine meeting was anticipated but this was to turn out not to be the case. Proceedings began normally enough as Joe was invited to begin the members’ progress reports.
His main contribution was to confirm that the cracks in his specimens had definitely extended during his tests, though the growth was small. Dorinda thought that this was an important result, though she pointed out that crack propagation would only be a problem if there were defects already present in the discs in the first instance. She believed that the rigorous inspection techniques employed, both at the manufacturer’s works and by the customer’s own inspection engineers, should guarantee that no such defects could be present in LP discs before entering service. This struck Dave as being a particularly significant point. It implied that some surface damage must occur whilst in service, before cracking could occur in high purity steam.
Dave followed Joe, presenting his latest results, including the suggestion of crack growth, of the pre-cracked specimens in his test rig, though it was early days. James, clearly pleased with himself, followed by reporting that at Slough they believed that they had made an important breakthrough. He thought that, when they heard the details, the committee would agree that a credible explanation for the turbine failure could at last be presented to the main Technical Committee. The other members, excepting Dorinda, were clearly taken by surprise at this statement and were intrigued to learn details. James, perhaps betraying his youth, was eager to enlighten them and with something of a flourish, produced copies of a draft report which, after assigning a number, Pauline distributed.
James began by saying that he had spent many hours poring over the power station records and had found what he believed was credible evidence for possible sodium hydroxide contamination of turbine steam, during the station’s commissioning period in 1965. Difficulties during commissioning of the sodium hydroxide dosing equipment, had resulted in several periods of considerable overdosing into the boilers. The Winford chemistry staff had been conscious of the need to maintain alkaline conditions during this, most important, early stage in the life of the plant. The presence of these high values, albeit only for short periods, at a time when the operation of the boilers was also being fine-tuned, could easily have led to sodium hydroxide being mechanically carried over in the steam. As the routine at the station settled down these problems were rectified. Consequently by the time Number 3 turbine was operational, the boiler water chemistry was strictly controlled and the turbine steam of high quality. He paused at this point awaiting comments.
Joe was the first to respond and he said that he was pleased that at least the possibility of contamination of the turbine steam could be envisaged, which would support the suggestion that sodium hydroxide was responsible for the failure. It suddenly occurred to Dave that Joe, with the best will in the world, might not be completely unbiased. He represented the turbine manufacturers, after all, and it was in their interests to support the view that an operational problem was responsible for cracking, rather than any shortcomings at the turbine production stage. He did not voice this thought, however, but said that, though he agreed that James’ suggestion was interesting, he felt that it was likely to be just one of a number of possible explanations and he would wish to await the results of the various tests in progress before going public. Henry characteristically did not hurry his response. He was a thoughtful man. When Dave had finished, he thanked James and acknowledged that his observations were important and may prove to be pivotal in the failure scenario. However, he went on to add, he was not clear how this latest information fitted in with the features on the fracture surface to which Dorinda and James had attached such importance previously.
“Well, now then,” began James in a rush. He was almost beside himself with his enthusiasm. Clearly this was just what he’d been waiting for. He reminded the others that he had spoken about features on the fracture surface of the failed Winford disc at the last meeting. These, he said, had been further examined and in the case of the overspeed ‘markers’, there was some evidence to suggest that approaching the crack tip, which was shortly before the final failure, the distance between these increased. This, he continued, indicated an increase in crack growth rate. There was a rustling of papers as everyone found the page. Additional support for this suggestion, he added with relish, was seen from a similar pattern of increased spacing between the staining marks. He’d also mentioned these at the last meeting as evidence of a chemical deposit build up, probably sodium hydroxide. This could possibly trigger an increment of crack growth. Using the overspeed ‘dating’ markers on the crack surface, he had been able to estimate the actual period when the crack growth rate increased and, comparing this with the details from the Winford Power Station’s operating log, this would correspond with a suspected operational error late in 1968.
James’ excitement increased as he made this announcement and it was only with an effort of will that he managed to contain himself. The others waited in silence as he recovered his composure.
He explained that the error mentioned in the log related to a trial that was being undertaken on Number 2 turbine at that time, which entailed dosing hydrazine directly into the LP turbine steam inlet pipe. By 1968, the dosing of hydrazine into the boiler water, in order to remove oxygen and increase alkalinity, was well established at Winford.
He continued, “This chemical is prone to dissociate within the boiler system and loses its effectiveness later on in the steam cycle.”
The trial mentioned was being conducted to evaluate the benefit of replenishing the hydrazine just as the steam entered the LP turbine. As this was only a temporary set-up for the duration of the trial, the dosing tank and pipework was not well labelled and colour coded in the usual way.
“We suspect that on the evening shift of 14th November 1968, one of the junior chemists may have accidentally contaminated this temporary hydrazine dosing tank with a small amount of sodium hydroxide solution, which was intended for the adjacent permanent sodium hydroxide holding tank. It seems more than a coincidence, I’m sure you will agree, that the timing of this incident, corresponding approximately with the time of our observed increase in crack growth, provides a plausible hypothesis for the introduction of sodium hydroxide into Number 2 LP turbine, less than a year before the disc failure.”
Silence.
Henry was the first to respond. He could understand James’ enthusiasm at this discovery. It could, as he had said, offer a possible explanation for caustic contamination of the steam in the case of the failed turbine disc. The coincidence of the timing of this possible error, with features on the fracture surface, was compelling. He congratulated James upon the clearly tedious task that he’d undertaken into the history of the early turbines at Winford.
Dave reminded the meeting that any hypothesis had to explain the presence of cracks in the discs on the spare rotor which had failed in the test at Runcorn. Dorinda responded to Dave’s remark by pointing out that the disc from the spare rotor, which had disintegrated during the Runcorn rig test, had previously been in service at Winford for around 30,000 hours before being refurbished and held as a spare. This rotor had accrued these hours in Number 1 turbine, from commissioning right through to the beginning of 1968 and therefore had been in operation during the early period of poor water/steam chemistry control. She continued by reminding Dave that it now appeared, from Joe’s recent results, that pre-existing defects could propagate during subsequent service in uncontaminated steam. This, they believed, could have been the case for vulnerable discs on the LP rotors in both Numbers 1 and 2 turbines. In the case of the failed rotor in Number 2 turbine, there was an extra suspicion of caustic contamination of the steam more recently due to a possible dosing error.
She concluded by pointing out that not only the SSA, but also other electrical utilities, would be gratified to learn that the cause of the Winford incident could, at last, be fully explained. Operators would be especially relieved to learn that the disc cracking was confined to the first two turbines at Winford and was associated with incidents of steam contamination. Therefore they could feel confident about the continued running of all other turbines.
Joe commented that on the face of it, this seemed a most plausible explanation for the West Winford incident, certainly the most plausible to date. He believed, however, that the details needed close inspection, not only by themselves within the sub-committee, but a mixture of academics and practical power station engineers, especially those with a knowledge of boiler operation. The whole hypothesis required verification and he felt that it was people such as the ones he’d mentioned, that could supply it. Dorinda said that she was pleased with the comments received and agreed completely with Joe. They had already addressed the need for wider comment and had initiated plans to hold a conference. This would take a few weeks to arrange, as they would wish to ensure that people of sufficient quality would attend and so, hopefully, arrive at an authoritative consensus. Dorinda concluded by adding that everyone realised how important it was for the whole of the power supply industry to solve this problem.
Dave travelled home in something of a daze. On the one hand, he realised that the main point of the sub-committee was to solve the problem of the Winford failure as quickly as possible and so accepting the Slough hypothesis would be good news all round. Nevertheless, he was despondent from his own point of view. Whilst he felt that he had represented SSD well and had initiated a viable work programme in a timely manner, he had barely made any contribution to the experimental programme. He had had such high hopes, secretly held, that this was his big chance to impress. He consoled himself with the thought that at least he had benefited by becoming acquainted with Professor Fletcher and the others, which wouldn’t do him any harm. He could only hope for other opportunities.