Tuesday 5 March 2013
A breach in the sea wall - Greenwich Peninsula
A BREACH IN THE SEA WALL
The river is an ever-present reality around the Greenwich Peninsula. Sometimes, when floods seemed likely, that reality became a threat.
The Peninsula's real name is 'Greenwich Marsh' where a network of sluices was built, probably, in the Middle Ages. Flood defences along the riverbank are always referred to as the 'sea wall' – a term which reflects the potential dangers of the tides. It is difficult to know when the original embankments against the sea were built – since they are mentioned in a document dating back to 1290. In 1528 they are referred to as the banks 'which had anciently been raised'. I would be very interested if anyone reader could tell me anything about the age of the sea wall. Clearly it is a very important structure, and, as the remainder of this article will show, requires the very best of engineering expertise. Without it much of the landscape of Thameside would not exist, as we know it.
Most of the records about the sea walls refer to times when the river had broken through. One early instance is in 1297 when there was a 'certain breach made in the bank betwixt Greenwich and Woolwich by the violence of the tides'. The problem usually was less a question of getting the breach mended than of persuading the locals to pay for the work.
From the 1620s the marshland was managed by the 'Marsh Court' or 'Court of Sewers' consisting of landholders and other interested parties who raised the 'Wall Scot' (the local rate) and employed a small staff. . A very full set of minutes for this body exists from 1625, which detail the care that had to be taken to maintain the marsh properly and keep the river out. This article is about one instance of a breach in the sea wall.
In October 1825 it became clear that a section of sea wall had become very unsafe and was threatening to give way. At the time two plans were made drawn but they don't give enough detail to be able to pinpoint the spot exactly. One appears to show it on the tip of the peninsula but, since the site was said to be 'opposite the Folly House at Blackwall', it may well have been on the western side of the peninsula at the southern end of the old Delta Works site. It appears that the problem was caused by a slight projection which made an irregularity in the line of the sea wall and a breach was threatened.
The Marsh Court had immediate legal problems in dealing with this because, not only was the work urgent and expensive, but members were unsure of their powers to acquire the site and have the remedial work done. Could they go ahead and buy the three acres of land, which were affected? If so how should they raise the money? Or did they need to get a private Act of Parliament first, to give them the powers to do the work? That would be the proper way to proceed but it would take time and the work was urgent. First they looked at 'Callis'. This was Robert Callis' 'Reading upon the Statute of Sewers' originally published in 1685. It had been edited and reissued as recently as 1824 – but perhaps the Greenwich Commission did not have the new edition. They found that that authority was 'full of doubt and contradiction' and so they sought a legal opinion. Unfortunately the barrister who they consulted also gave an opinion that the matter was not clear and he told them to get another opinion.
The Court also began negotiations with the owners of the site – because there was an issue of land reclamation they felt it was important to acquire it. It was occupied by a Mr. Newman, a butcher who used the land for grazing, and the Commission had had the impression that he was the owner. This was not so. The land was actually owned by a Mr. Powis.
It was decided in due course that it would be simpler and quicker for all the landowners to sign an agreement allowing the commissioners to buy the land and that they would also agree for each of the landowners to pay a sum of money. It was suggested that the actual purchaser should be Morden College, the wealthy charity that already owned a great deal of land in this area - and of course is still a major landowner here.
An estimate for the work was sought from John Rennie. This is the younger Rennie whose more famous father had died four years previously. He was currently involved, among other things, in completing his father's work on London Bridge. In the future he was to undertake many projects involving marshland reclamation in the fens but he had already been appointed as Chief Drainage Engineer for the Eau Brink so that drainage, and perhaps embankment, was already an interest of his.
Two months later Mr. Bicknell, solicitor to the Commissioners gave an update on information obtained to a meeting at the Green Man Pub, then at the top of Blackheath Hill. This meeting was packed with representatives of local interests.
Rennie reported on what he thought was the cause of the problem. Rennie felt that the great variation in tides throughout the year 'tends to carry the bank away' and that previous remedial work – 'a wooden framing consisting of poles and land ties' together with 'several hundred tons of Kentish ragstone' was making it worse. The wall would have to be rebuilt. The Court was not impressed with the cost of Rennie's estimate and asked if he could find an alternative, and cheaper, way to solve the problem. Rennie made a second site visit and reported a few days later. He said that the only other possible alternative scheme – to use piling would be even more expensive. He then sent in his bill for this second consultation.
Meanwhile the Court had asked if a report could be obtained from Thomas Telford. He was at, the age of seventy, nearing the end of his long career. He was the 'undisputed head of the civil engineering profession in Britain'. He had considerable experience in the Fens and was soon to work with John Rennie Jnr. there. The meeting at the Green Man had, however, asked for the most prestigious engineer that they could.
Telford too made a site visit. He to pointed out that the exposed position of the portion of bank which had caused the problem. The river narrows slightly at this point and he also drew attention to the new West India docks and the number of vessels which were 'frequently moored adjacent to their entrance' constricting the flow of water. The river thus rose with 'increased violence' and was 'continually grinding the soft matter from the bottom'. He felt that there was an imminent danger of a breach in the wall.
Neither engineer mentioned the Blackwall Rock which had been removed from the northern side of the river about twenty years previously.
Telford, Rennie and the members of the Court of Sewers all thought that the activities of lightermen employed by the City of London and Trinity House were not helping. It was alleged by everyone that material was being removed from the foreshore in this area for use as ballast. The Commission duly wrote to those authorities to point this out asking if this had been going on. Replies, from the Lord Mayor and the Elder Brethren, were, predictably, non-committal.
Telford was however asked to do the work. The archive includes his detailed specification. The work basically consisted of a new earth bank built in such a way as to make the line of the sea wall completely smooth. There was to be a drain at the bottom of the inner slope and the whole structure covered in turf. The work was to be supervised by the Commission's Wall Reeve who received an enhanced salary for the job. Two contractors tendered for the work Thomas Cotsworth of Dover Road, Southwark submitted a price of £2,100 and Simmons of Bromley, Kent, who got the job, for under £900.
The work was finished by the summer of 1826, apparently without problems, Telford's final inspection took place and his certificate of completion was issued in July. A dry dock was built in this part of the peninsula in the 1870s but otherwise it is likely that the line of the bank is much as Telford left it, although a very considerable amount work has been done to the wall itself in the intervening years.
A year later in July 1827 Telford wrote to remind the Commissioners that he still had not been paid for the job. It was around the same time that Telford, in the company of Rennie; working on the Nene outfall in the Fens was to catch a severe chill, the first sign that he was beginning to fail with age.
Telford was not alone in not having been paid his services – a series of letters had already been received from Rennie. These concerned his bill for £30 in respect of the second estimate, a sum that the Commissioners refused to pay. In October 1826 Rennie had written to say that he had been in Ireland but that his brother, George, had informed him of the outstanding bill. He wrote to them that he had 'charged only what I conceive myself entitled to' and in April 1827 that 'nothing annoys me more than disputes about money matters'. The Commissioners recorded that they 'did not find it necessary to alter their first determination'.
Within the next few months the Commissioners also received claims for compensation for late payment from the original landowners. This was a Mr.Richard Powis. The original owner had been his father who had just died – Powis wanted £50 as compensation for late payment.
There is just the suspicion that this archive might have survived because of the arguments over payment. The job must have been a relatively small one for Telford and Rennie, but very important in terms of Thames flood prevention. Few visitors to Greenwich will realise how the care and maintenance by the Marsh Court, its predecessors and successors, over many centuries has kept the land safe and made development of the area today possible.
This article has been prepared from archive material in the Greenwich Commission of Sewers archive plus some material on 'imbanking and draining' in the possession of Woodlands Local History Library. Biographies of Telford and Rennie have also been consulted. It first appeared in Bygone Kent in 1998
 L.T.C.Rolt, Thomas Telford. 1958
Posted by M at 18:57