Tunnels, Locks, and Losses Although James Morgan Took Great Care

Talk 5: Tunnels, Locks, and Losses Although James Morgan took great care setting out the line of the canal the task was fairly straightforward. It must have been a rather more daunting task planning and executing the first tunnels, which were driven through the ridge separating Paddington basin from Regents Park. There were a number of tunnelling methods in use and the most popular took their names from the areas where they were apparently favoured. There was the Franco-Belgian system, the German system and the Austrian system to name but three, but Morgan decided to use the English system, as, probably, that was the one with which his workers and associates were best acquainted. One of the main problems facing even the most experienced tunnellers, no matter what method they used, was paucity of geological knowledge for, even after test borings, it was difficult to know what problems would be encountered until digging started. John Sutcliffe thought tunnels should be avoided altogether, if feasible, as they were expensive, of uncertain durability and dangerous to build and use. I am sure Morgan would have liked to have found an alternative had it been possible, flights of ascending and descending locks for example, but realistically this would not have been economic. Under the English Method a temporary arch was constructed at each of the tunnel entrances. This arch was a canopy, acting as a protective shield and underneath which miners would start to dig. As they widened the hole and dug down at the sides these workers would support the surrounding earth with stout timbers, backed by protective boards. Great care would be taken to ensure the canopy was well supported, larch being the preferred wood because it gave warning of excess stress by creaking. When the shield was completed and there was enough space underneath, bricklayers would lay the sides of the tunnel. To ‘turn the arch’, as rising the brickwork was called, large wooden frames, called centring, would be erected, which would be almost as big as the shield. Boards would be set horizontally behind these wooden frames and courses of bricks laid on them. As courses were raised miners gradually dismantled the shield, replacing it with rammed earth. Looking up from the tunnel floor when a section of the brick arch was on the point of completion a visitor would see only a thin strip of keystone bricks, the rest being hidden by the underside of what seemed like the inside of half a giant wooden drum. To minimise dangers of a roof fall, a constant threat in unstable geological conditions, the protective shield moved forward in lengths of between 9 and 12 feet, new diggings always starting at the top and the protective shield being shifted forward as bricklayers completed their work. In theory, if all calculations had been correct, when the two tunnelling teams broke through they would find they had a perfect match. Supervision of the Maida Hill tunnel must have been very taxing for Morgan, especially as he had been responsible for the design. He was, however, probably pleased the work was not sub-contracted, having been instructed to use direct day work. Where tunnels were built by piece work, pressures from the workforce, as well as swelling clay, could signal danger. One tunnel engineer cited a case of miners being urged to speed up by bricklayers. The bricklayers, naturally, wanted to maximise their earnings, but if the miners did not take great care in their work everybody’s safety would be jeopardised. At first all went well at Maida Hill. Deep cuttings were made to the entrances, then mining began and the wooden canopies steadily advanced. Unfortunately, on approaching the centre of the ridge, there were ominous and unexpected signs of an underground spring. Extra labour had to be recruited to deal with the problem and expensive timber left behind the brick lining to help retain running sand, which was as tricky to deal with as spring water. Although anti-flooding work brought serious casualties amongst the workers, it is unclear if there were any fatalities and at least a repetition of the Highgate Arch disaster was avoided. Building the little Eyres tunnel must have been easy by comparison, although deep cuttings had to be made close by. At this point an accident occurred which did result in deaths. It was recorded in a press report. A shocking accident ocured on Friday week at the Regent’s Canal close to Chalk Farm. A few minutes before eleven o’clock as the workmen were preparing to fill some waggons, twelve men who were lately taken, not being aware of the danger, ventured too close in undermining the bank, at a depth of 25 ft. when suddenly the bank fell and completely buried them; eight of them were dug out alive but four with their legs and arms broke and the other four much bruised; six of the eight are in such a state that their recovery is not expected. After a length of time, four more were dug up quite dead, and their bodies removed from the canteen for the Coroner’s inquest. As the company engineer Morgan could never concentrate on one thing for too long and although completion of the canal to the west of Hampstead Road was a priority Morgan had work to do on the rest of the line too. This, inevitably, brought him into contact with William Agar. One day, in the spring of 1813, whilst Agar was out, Morgan visited Elm Lodge. Morgan left before Agar returned, but a letter of complaint followed him. According Agar Morgan and his assistants had traversed repeatedly over gardens, plantations and other parts of my Estate as if for the purpose of doing me injury, and committing acts that would be unpleasant to me. The lawyer asserted the company had no power to make the canal where the line had been set without permission, something he was obviously not about to give. When asked for a response Morgan told the directors he was following instructions, had kept to the line drawn on the plan filed with the Clerk of Parliament, that Agar’s servants had been informed of what was happening and no more injury than necessary had been From the director’s point of view this skirmish must have reinforced the feeling that dealing with Agar would be far from easy and also the suspicion that his obstructiveness was just a way of squeezing money out of the company. At the end of the day Agar’s estate could, unlike the ridges through which the tunnels were bored, be skirted, but there could no avoidance of the need for water and this was something to which Morgan had to constantly give attention. Water saving ideas were, naturally, welcomed and one came from a well known inventor, William Congreve. William Congreve, much in Britain’s spirit of the times, seemed to be forever applying science and trying to improve technology. This culture of development was one reason why British industry was so far ahead of its counterpart in France where the ‘pure scientist’ excelled. Indeed, when Josephine kissed Napoleon’s cheek (which was not often incidentally, as he was much fonder of kissing her than she of kissing him) she could relish the smoothness of his cheek because her husband used superior English razor blades. Napoleon had less reason to thank Congreve than the manufacturers of his razors. Working at Woolwich, where his father was Comptroller of the Royal Laboratory, Congreve had been responsible for the development of rockets captured in India, the results so impressing the authorities that they were widely adopted by the British Armed forces. He also used his talents beyond warfare, making, for example, a new type of rolling-ball clock that he presented to the Prince of Wales. Already impressed by the rockets, the prince invited him to become an equerry and, although not a regular soldier, he was gazetted a Lieutenant-colonel in the Hanoverian Artillery, which is why he was often referred to as Colonel Congreve. Elected to Parliament in 1812 he did not let his parliamentary duties interfere with his inventiveness, directing his energy to a new type of naval gun and the question of saving water on canals. In May of 1813 Colonel Congreve patented a ‘hydro-pneumatic double-balance lock’ and invited Colonel Drinkwater and other directors to see a working model. Theoretically, his idea seemed a good one, for he proposed to use boat lifts powered by compressed air. If the locks could be made to operate successfully there would be a huge reduction in the amount of water needed by the canal, so it is easy to see why it appealed to Morgan. Congreve’s intention to develop and sell licences for his locks was supported by the remarkable engineer Henry Maudslay. Maudslay was almost the same age as Congreve and also had links with Woolwich, where his father, a badly wounded soldier, had been a storekeeper in the arsenal. When starting out in business Maudsley set up a workshop close to Oxford Street where his fine quality products caught the attention of Marc Isambard Brunel, for whom he subsequently built a series of machines used in the manufacture of rigging blocks needed on sailing ships. This success drew in more orders so he moved to larger premises in Lambeth, where production of a wide range of machinery and machine tools began. If anyone could manufacture Congreve’s lock to the tolerances needed it would be Maudslay and after viewing the little model the directors voted £300 for the construction of a much bigger one.

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