Pluto

I usually go Friday or Saturday as I have to deliver the new edition of Waterways Journal. This year there are articles on Tom Rolt, canal traffic around Chester, tar and associated canal traffics (but not TCLtd), and Whitebirk (Blackburn) boatyard.

There have been a lot of comments on restored boats here. Perhaps a little more thought is needed as to exactly what it is hoped to be achieved by conservation or restoration. Twelve years ago I wrote a report for the museum at Goole regarding the conservation/restoration of the tug Wheldale. The introduction included the following: When preserving an industrial object, there are three main possibilities which should be considered. The adoption of one of these criteria will then dictate the methods to be used in preservation. 1: To conserve the object as an example of its type. Today, this would mean keeping the object in its ‘as worked’ condition, just as it had finished working. Previously the object may have been returned to its original, ‘as built’ condition. 2: To maintain the object, using traditional materials and methods, in order to preserve and record the traditional skills used in maintenance and operation, as well as preserving the object itself in a condition similar to that when in use. 3: To maintain the object, using modern methods and materials, in such a way as to be able to operate the object regularly and safely, and thus to be able to reserve the traditional skills of operation. From the start it is important to decide what is to be achieved by conservation or restoration. Do you want to keep the boat as an example of a particular type at the time it was removed from service, or do you want to preserve the skills and traditions which are associated with the boat. Whatever you do, recording should be carried out of all work affecting the boat if conservation or restoration are to be achieved 'professionally', and this is the one area where museums tend to be better than individuals.

I have a list of the age of lock gates on the L&LC in the 1920s. The oldest, on the Rufford line, was 45 years, with one of the shallow locks at Appley having head gates 41 years old. At Parbold, on the river near Chapel House, there is the site of one of the Douglas Navigation locks. I suspect that there could be remains of the chamber and gates, but it would need an archaeological dig to see what remains. The navigation was last used in 1781.

I would expect that the name comes from a lock keeper or other canal worker rather than something/someone non-canal. This was certainly the case on the L&LC where Handcocks Bridge in Aintree was named after the bridge keeper installed by the canal company after the Earl of Derby complained about the bridge being left open. There is also Sam's Lock, the second lock up at Blackburn, which was named after the lock keeper.

It looks very similar to the traditional Leeds & Liverpool boat stoves, though they were made from cast iron. You need a hole above the fire so that you can use a baffle. Two sizes were usually available; a full one for starting the fire, and a half one which could be useful when windy and smoke got blown back down the chimney. You also need a trivet to clip on to the top of the front fire bars so you can have a kettle on the boil all the time. The L&LC ones often had designs cast into the front plate. In Lancashire, the stove pipes were round, while in Yorkshire they used square wooden chimneys lined with thin steel plate. I am, as part of the L&LC Society, thinking of producing castings for the grate, front and top plates so that replicas could be fabricated a little more easily than yours - which I think is excellent.

The census is particularly bad at recording the boating fraternity. It is supposed to record where everyone was at midnight on a specific day, but would have taken a couple of weeks to compile. What do you think a boatman would say when asked 'were you here at midnight five days ago?' Having looked at much of the census material for the L&LC area, 1841-1881, each year there are very few boatmen, certainly many less than 100, at a time when there were around 1000 boats working on the canal. The most interesting returns are those done specifically for recording boats which IIRC date from 1861 or 1871.

Many of the C&HN records were burnt just before nationalisation, so I have been told. One source of boat detail could be the A&CN gauging books which are in the archive at Gloucester. I did look briefly at them some years ago and seem to remember a number of narrow boats listed.

That's exactly what most people said about L&LC short boats when I moved onto Pluto in the 1970s, yet the shape and skill needed in constructing short boats far exceeds that needed for narrow boats. It was/is just that people don't have the background knowledge to appreciate boats which are not well known. Little has been written in English about the peniche, but if you do some research, you would find that the reasons for their shape mirrors that of narrow boats. Both have a certain charm in the shape of the bow and stern, but the rest is just a box when compared to real boats. That said, the world would be a poorer place without either. The French have ben very good at getting EU money to build replicas of many old traditional boats, and I can recommend the bi-annual festival held at Orleans on the Loire, where around thirty boats attended when I was there a few years ago. However, these boats are comparatively small - up to short boat size - and there has been no similar tale to tell regarding the restoration of larger wooden canal and river boats there.

I think one problem with discussing Chinese canals is that some engineering structures, although having similar names to those in the west, actually perform slightly different functions. Many Chinese canals were/are used for land drainage and irrigation as well as navigation, so their solutions to change in level are somewhat different to those used in Europe, where many canals were primarily for transport. The Grand Canal was also only used for shortish periods each year, though quite intensively then, for the movement of rice from the Yangtze basin to Beijing and for the returning empty boats. This traffic also had to fit in with the varying flows of the Yellow River, and the so-called locks at the river junction were designed to keep the vast amounts of silt being carried down the river from entering the canal system. More conventional flash locks and inclines were used elsewhere. As you mention, the type of structure for coping with changes in water level varied over time. The chinese are putting together a World Heritage application for the Grand Canal, and I hope that more information about the history of Chinese canals will be published as part of the application.

There may have been pound locks on early Chinese canals, though by the time the country was visited by Europeans, in the 18th century, these had been removed and replaced by inclines and flash locks. The earliest canal in China was the Lingqu or Magic canal, first constructed circa 240 BC. The canal links the head waters of two rivers in quite mountainous country. It is still there and can be seen at 国宝档案20081216 -- 揭秘灵渠(下) http://www.youtube.com/watch?v=qQIDGW-MWEE...feature=related The 1200 mile long Grand Canal came later, being constructed from 600AD. Its route has changed considerably over the years, not least because of the silting and movement of the Yellow River which carries around 10% by volume of silt. Its estuary has moved quite suddenly some 400 miles north or south on several occasions, causing problems for those maintaining the Grand Canal. The development of canal technology in China has still to be researched fully. There are copies of scrolls illustrating the canal in the 18th century at http://www.learn.columbia.edu/nanxuntu/htm...oll_index.html# By that time flash locks and inclines were the norm, though not necessarily as we know them in the west. A theory has been suggested by some historians that the idea for the pound lock was brought to Italy by the Chinese, who sent a fleet of boats westward on a voyage of discovery around 1428.

I suspect some form of water gate. Chamber locks developed where there was insufficient water for flash locks, and their introduction would also mirror an increasing need for uninterrupted passage by boats. On an early canal where the tideway ensured water levels, there would be little point in boats leaving the canal at other than high water.

I do have copies of original sketches for the shielded lights proposed for L&LC boats during the 2WW.

It's not this aqueduct, which is at Briare, but one further up the Loire Lateral Canal which has a two-rise lock at one end. Briare is worth visiting as it is the end of the Canal de Briare and the canal link into the river opened in the 1640s can still be found, along with the original river crossing constructed as part of the Lateral Canal before the aqueduct was built. Also in Briare are the warehouses used for storing wine on its way to Paris, and further along the canal are the now-bypassed seven-rise locks at Rogny. They are of particular interest as you can see how they were lengthened at one stage by progressively extending the lower end of each chamber. Construction of the locks began in 1610 and was finally completed in 1642.

Bet they worked overtime writing the report!

The Chinese had canals much earlier than this, probably c600BC. In Europe, lock gates were introduced circa 1100AD on the flood prevention schemes around the Rhine/Maas delta, notably at Vreeswijk and Spaarndam. They could have been single or double gates which probably folded back against a beam fitted across the navigable opening. Flash locks, using simple gate technology, were also introduced, with the Stecknitz Canal between the Elbe at Lauenburg and Lübeck opening in 1398. It was Europe's first summit level canal. Mitre gates date from the opening of the Canal de Bereguardo near Milan, circa 1458, built by Bertole de Noviate IIRC, with Leonardo da Vinci designing his own particular type of gate paddle on the Milan ring canal in the 1490s. He was thrown out of Milan and ended up in France, which may be the reason that France then became the centre for waterway technology. The Brussels Canal, circa 1610, had the first ground paddles, with construction of the seven rise flight at Rogny on the Canal de Briare beginning in 1610. In Britain, we were slow to take up the technological advances on the European mainland, though John Trew did use mitre gates on the Exeter Canal in 1566 and subsequently on a couple of River Lee locks where it is probable that they were called turnpikes, years before the term for roads. However, simple flash locks continued to be used extensively, followed by turf sided locks. Guillotine gates were unusual as they restricted the size and type of boat at a time when sails and masts were an important form of moving boats. Many canal Acts had a clause which required locks to be left full. I suspect it was to ensure that the wooden gates did not dry out, to keep water pressure against the sides of the chamber to reduce the likelihood of them collapsing, and because excess water would then flow over upper gates, through the lock and over the lower gates without causing erosion problems in the chamber.

Apart from the ones that only worked below Wigan called long boats.......

As mentioned in my earlier posts, with a single gate the force on the gate is in line with the chamber wall. For an upper gate this poses no problems as the wall along the length of the chamber provides sufficient strength. However, lower gates take much more pressure because of their height, and it may have been thought that there was insufficient wall to the tail of the lock below the gates to provide sufficient strength. By using two gates, much of the force is diverted at an angle into the side of the lock, and this was overcome by increasing the strength of the quoin and gate anchor area, which would have been good practice anyway. If a single lower gate had been used, the tail of the chamber may have needed extending to cope with the larger forces, and extending these was where additional cost would have been necessary. It would be interesting to compare the length and structure of the chamber tail walls for single and double gates. Were they substantially longer for single gates, or had they decided that there was sufficient strength in standard length tail walls by the time single gates were introduced. Sorry for the double post! Mike

As mentioned in my earlier posts, with a single gate the force on the gate is in line with the chamber wall. For an upper gate this poses no problems as the wall along the length of the chamber provides sufficient strength. However, lower gates take much more pressure because of their height, and it may have been thought that there was insufficient wall to the tail of the lock below the gates to provide sufficient strength. By using two gates, much of the force is diverted at an angle into the side of the lock, and this was overcome by increasing the strength of the quoin and gate anchor area, which would have been good practice anyway. If a single lower gate had been used, the tail of the chamber may have needed extending to cope with the larger forces, and extending these was where additional cost would have been necessary. It would be interesting to compare the length and structure of the chamber tail walls for single and double gates. Were they substantially longer for single gates, or had they decided that there was sufficient strength in standard length tail walls by the time single gates were introduced.

There are three surviving in Britain: at Newport, South Wales, Middlesborough, and a private works one over the Mersey in Warrington. Amongst the others elsewhere, there is one in regular use over the Kiel Canal in Germany.

With single gates, the thrust is in line with the chamber wall which does not need to be as strong as for mitre gates, where the thrust is outward. That said, the stone or brickwork does need to be strong enough to resist that inline force. In the case of mitre gates, there needs to be more reinforcement around the gate anchor to resist the outward thrust. On chamber walls, the forces also vary in direction depending upon whether the lock is empty or full. This is why the curved chamber walls used on the Canal du Midi were not widely used elsewhere as their design did not take into account the loading caused by the water when the lock was full.

We used to use them quite regularly when restoring old machinery for museums. Keeping the needles blunt gave a better surface for painting as there were no high spots to poke out. However, we went over to sand blasting where possible as it was much quicker and more effective.

From an engineering point of view, two mitre gates would provide a better seal than a single gate. They would cost more as chamber walls would have to be made stronger to resist the side thrust created by mitre gates. As mentioned previously, on all canal as originally built, ground paddles were fitted around upper gates - they were introduced to Britain by Thomas Steers on the Newry Canal c1742 - and gate paddles were fitted to lower gates. Upper gate paddles were fitted in the mid-1800s to speed traffic and help competition with railways, though in general this seems to have happened on only the more successful canals. Changing from single to double gates could have been done then for the same purpose, though I don't think so as I have copies of early-1800s drawings showing double bottom gates on T&MC locks. Single gates would certainly be cheaper as they were not so dependent on the strength of the lock chamber. Early locks could have wooden floors, with the stone chamber walls built upon the woodwork - some still survive on the L&LC in Yorkshire. This would allow the walls to move independently and could cause problems with the seal on mitre gates. Poorly constructed brick or stone inverts could result in the same problem, and modern locks built in mining areas likely to be affected by subsidence invariably have single leaf gates, usually lifted vertically. Such gates are fitted to all locks on the canals in the Ruhr, and Pagefield Lock on the L&LC below Wigan had one for a few months when the lock was installed to cope with subsidence. Basically, it could be that mitre or single gates were installed at the whim of the engineer to cope with water conservation, cheapness of construction and solidity of foundations as he saw fit. Conversion to speed traffic in competition with railways is unlikely as the introduction of upper gate paddles was a much cheaper solution at a time when money would have been scarce.

Woollen fullers collected lant, but you probably think I'm taking the p**s.

Having looked again, it could well be from Stanley Road. The Carolina Street canal company warehouses were built in 1884 and extended in 1892. They were built to serve the new north docks. Prior to that, the towpath was on the right. The towpath was used for telegraph poles from the 1870s IIRC, and their location in the photo would then be correct. The two change-line bridges here were built at the same time as the warehouse, the wall and towpath on the left dating from the same time. There was quite a community of boatmen's families in the terraced housing around Carolina Street, the NWM holding a boatman's gansey which was knitted by one of the wives, probably in the 1930s. I have had a pattern for knitting one taken from the original, though converted to a jersey, ie knitted in sections rather than in one piece as is a gansey, and it can be downloaded from my web site http://www.mikeclarke.myzen.co.uk/Downloads.html under the Leeds & Liverpool Canal Society section.