Tuesday, 30 December 2008

New Sleaford Lift Bridge

On a bitterly cold 29th December the bridge finally arrived in Sleaford! The crane arrived on site about 7.30 in the morning to set up, though I have to be honest that was before I arrived to view the events!
At first sight the bridge looked a bit like a giant Meccano Kit with two large artic lorries carrying all the parts. The first part to be unloaded was a large frame, a jig, for the bridge to be assembled on. This made sure that all of the parts were in the correct alignment for a quick and accurate assembly. First to be put in place on the assembly jig were the two ends. This was achieved with a few lifts from the crane and use of crowbars from Briton’s assembly team to sit the ends in the correct place. The second lorry was then unloaded with the counterweight, lifting deck and joining beams being put onto the ground next to the main assembly.

The next part to be assembled was the lifting deck. This had to be a very careful lift as the deck had to be lifted at an angle so that the pivot points had room to fit into the slots made for them in the end part. After one or two tries and some adjustment to the lifting strops to get the correct angle this was eventually achieved successfully.

The next stage was to lift the four joining beams and bolt them into place. This took place fairly quickly with the two beams on one side being lifted and bolted up closely followed by the two beams on the other side.

All this work took till lunchtime. Time for a quick sandwich and a warm up in the car! After lunch it was a case of a final tightening of all the bolts with an air spanner to prepare for the big lift. This was going to be best viewed from the New Street side of the river. Unsurprisingly a number of local Trust members were present at this time! Excitement mounted as we could see the assembly team placing the lifting strops onto the bridge and the crane swinging into position.

The crane revved up and the bridge, minus the counterweight, was lifted up and over the trees. This was quite a height, in fact, big as the crane was, it was nearly at its full reach.

The new abutments were ready to receive the bridge, the team having already removed the nuts from the anchor bolts. Despite one or two doubters who thought that the bolts weren’t lined up correctly, the bridge dropped into place with little fuss or effort and the lifting strops were finally removed.

The last big lift of the day was to put the counterweight into place. This was not part of the original lift as it would have contributed an extra four tons to the overall weight and would have made the lift very unbalanced. The assembly comprised mainly of bolting the pivot bearings to the main structure and fastening connecting rods from the counterweight arm to the end of the lifting span.

With the counterweight in place the final shape of the bridge was complete.

The only work that now remains to be done is to fit the mechanism to raise the bridge and also to make good the access walkways either side of the bridge. Both jobs should be happening by the middle of January.

Sunday, 30 November 2008

After quite a while in the planning the refurbishment of Bottom Lock was finally finished in early November.

Much research was carried out by Dave Pullen to try and establish how the lock was dammed off when the lock was originally restored in the late 1980's as nobody could remember how it was done. All we had to go on were a few black and white photographs so any details were, at best, sketchy.

The contract for piling off the lock was awarded to Black Sluice Drainage Board but when they started to put the piles into position they hit an obstruction. This resulted in twice as many piles being put further away from the lock at double the cost.

Before the new gates could be installed Trust volunteers had quite a bit of work to do. This included repairs to the brickwork on the lower wingwalls and also brickwork repairs in the lower gate recesses. Under normal circumstances neither places are easy to access. When we were carrying out the repairs we were careful to leave a few holes in the wingwalls for nesting Grey Wagtails as it had been established that the area was one of the few sites in the county that they nest.

As the lock was going to be drained for a while it was also decided, as a safety measure, to take the opportunity to fit lock ladders.

The new gates that had been manufactured for us by Hargreaves of Halifax arrived on site on 5th November and were quickly fitted into place by Nigel Lord and his team. Gates were quickly followed by the balance beams and the paddle gear. The next couple of days were taken up with final adjustments to make the gates fit correctly.

There were, however, a few diversions during the work. One particular one comprised an unscheduled fish rescue. During the initial draining of the lock Dave Pullen and John Line made sure that all the fish had been rescued. Later on though the water level rose for a short while and a Pike managed to make his way into the lock. We didn't have a net so we managed to encourage the Pike into a large plastic bucket which we hauled up the lock wall and then released it above the lock.

With a view to future maintenance of the lock Dave Pullen decided that while the lock was drained we should fit grooves in the lock entrance for stop planks. This meant that we also had to fit a beam into the lock apron. On the Sunday a small select team of volunteers lowered a concrete mixer into the lock and proceeded to mix about 2 tons of concrete to provide a haunch either side of the beam.

The water levels were a bit changeable and although Dave Pullen had intended to raise the top gate and 'christen' the new gates was beaten to it by the river. In fact the team from Hargreaves only just manage to finish and get their gear out of the lock before the river came up and flooded the lock.

Many thanks to Dave Pullen for all his hard work organising the program of works and also to Norman Osborne for his efforts transporting materials and equipment.

Dave Pullen

Norman Osborne

Monday, 24 March 2008


The recent storms have caused an amount of damage on the Slea. On Saturday 1st March we received a phone call from the staff at Cogglesford Mill to say that two trees had blown down just below Cogglesford Lock and, ���������What could we do about it?��������� Our intrepid photographer, Debbie Scott, went down to have a look and confirmed that the situation was indeed quite serious. The two trees had blown down and, although not blocking the river, were blocking the footpath on the far bank. The following day was a work party so after the main task was completed a small number went along to assess the problem. On looking at the task it was decided that, although we had the tools to clear the footpath, it would make the situation more dangerous for the general public. The reason for this was that as the trees were falling they broke some of the branches of the trees on the other bank and some of them had not completely broken off and were swinging in the breeze. Any clearance could have left the Trust liable if there had been an accident. The Trust are grateful to Andy Martin who managed to get down to the river on the following Thursday to clear away both of the trees and to make the area safe.

Series of photos showing the trees after being blown down, during removal and the scene afterwards.

Saturday, 22 March 2008


Before refurbishment can start in the Summer there is a certain amount of preparation to complete, so on the 17th February a Work Party was held at Bottom Lock to carry out some initial work. An Ecological Survey had been carried out for the Trust by consultants ESL to check that there were no protected species in the area of the proposed works. There were no potential problems for us but it was recommended that any vegetation in the area that could be used as cover be stripped back to deter nesting, etc. This was our first task of the day but, in the event, little vegetation needed to be removed from the area.
The second task determined by our Engineer, Dave Pullen, was to find out the profile of the river bed below the lock so that a dam can be designed to ready the area for the work on replacing the gates. This was quite a complicated but low-tech process involving a boat, a rope, two men and a long pole. The task was achieved in the end but did afford some amusement to onlookers. Those who bet on a sinking were disappointed!

A general tidy up also took place and there was a large bonfire of wood gathered and piled up during previous work parties.
Steve Hayes
Two men and a pole

Two men and a Boat
Classic conversation of the day. Dave "Norman. My end's sinking." Norman "Well my end's OK"


The restoration of Bottom Lock was an early major achievement of the Sleaford Navigation Society and opened up the waterway from Chapel Hill to Cobblers Lock. Sadly, over the years time has taken its toll on the bottom lock gates and, in spite of some valiant patching they are looking very much the worse for wear and are in need of replacement. Thanks to Lincolnshire Waterways Partnership we shall have a wonderful new set of gates made out of Ekki from sustainable sources. All those who have used Bottom Lock will remember the mechanism to raise the top guillotine gate! 350 turns are needed to raise the gate to allow a boat to enter or leave the lock and a further 350 turns to lower it again when you have passed through! It can be possible to persuade young children that turning the handle is great fun but it has to be said that this ruse is quickly discovered to be a con! New gearing will now mean that far fewer turns will be needed to operate the gate to the delight of all users! Plans are also in place to install floating moorings above and below the lock which will make access both easier and safer. The current landing stage below the lock, shown on the photograph, is somewhat limited and awkward to use. At present there is no landing stage above the lock and this makes alighting from the boat there quite an athletic process! The new landing stages will also aid the portage of canoes around the lock. We are delighted that these improvements will make boating on the Slea a safer and more pleasurable experience. Bottom Lock is held in affection by many people who travel there by boat or on foot and it’s hoped that new seating there will make visiting even better.

Chris Hayes

Friday, 21 March 2008


After consultations with Sleaford Town Council and North Kesteven District Council it was decided to revise plans for the Winding Hole and Slipway to take into account their comments. To help produce a more professional look to the project the Trust was authorized by Mary Powell, from Lincolnshire Waterways Partnership, to engage a firm of consulting engineers to produce a new solution acceptable to all parties. The Trust has also commissioned a survey of the trees in the area to ascertain any potential problems. A draft plan has been produced which is now under discussion and seems to satisfy most of the criteria.

Design for the Winding Hole and Slipway
The Trust will be shortly resubmitting a planning application for the works with a view to starting work as soon as is feasible afterwards.


Although, on the surface, little appears to have been happening with the bridge recently there has been a lot of behind the scenes preparation work going on. One problem has been that there are water and electrical services under the existing bridge which need to be moved before any other work can happen. The orders for the diversion work was put in place about six months ago. The water pipe was the first to be moved and, we believed, shortly to be followed by the diversion of the electrical cable. Unfortunately the original route proposed went through the area where Sleaford Town Council are going to build their new offices. When the electrical company were told of this they went away for a rethink, unfortunately this coincided with a change both of company and personnel, resulting in a long delay. The latest date we have been given for the new works is "sometime in March". One consequence of the delay has been that any construction work on the bridge will be into the nesting season for the water birds on the river. Not wanting to cause any disturbance to nesting birds we decided that the best course of action would be to take advice from experts. Accordingly we contacted the Environment Agency and also a firm of Ecological Consultants who specialise in river corridor work that the Trust used to carry out a variety of environmental studies commissioned in the past. Their advice was to deter any birds from nesting for a distance of 15 metres from the place where work would take place. One thing, though, was important and that was to put in place mitigation measures. This meant that if we took any nesting areas away we should create new ones. On Sunday 2nd March a small work party from the Trust gathered in Eastgate Car Park. The first task was to establish that no birds had laid eggs in the working area, to our relief this proved to be the case and we were clear to work. Fortunately the reeds were easily moved and, with the aid of a wheelbarrow, were moved about 100m downstream and replanted.

Sleaford Navigation Trust Blog

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