The story of Wortley Top Forge has been one of restoration and development since the Society took it over in the 1950's. Here is a first hand report by Duncan Smith on what this means in real terms to those involved in the work. (Mick Johnson - Editor)
The first operation was to jack and pack the entire wheel, shaft and cam up and out of its bearings. The helve was jacked up and packed to give as much clearance as possible underneath. Both bearing housings were then removed. The whole assembly was then jacked and packed to a height where the wheel collar or insert was clear of the stonework of the wheelpit. At this stage the wheel was supported by girders going through the wheel and packed at each side on to the stonework, the shaft and cam being supported independently.
A tedious task was now to remove the old wrought iron wedges and semi-rotten oak from between the wheel and the collar, and the shaft, by allowing the shaft to rest on the packed up wheel. This slackened off the wood and the wedges at the top. This was removed, also one side of the vertical. The shaft was Jacked up. This released the rest of the wood and the remaining wedges. Iron bars were placed between the collar and the shaft with the collar resting on them. The collar was then barred along these iron bars into the forge until it was clear of the wheel and over the stones of the wheel pit. The shaft was lifted again, lifting the collar with it, which was lowered on to the packings.
At the same time a wide short girder was packed up level underneath the cam which weighs approximately 3.5 tons. A machinery skate was placed between the cam and the flat inside web of the girder. Two light girders were packed up then, one on either side of the shaft. The shaft then rested on heavy duty rollers which were spanning the girders. The shaft and cam were then jacked endways into the building unit it was completely clear of the wheel and the collar. The shaft and the cam were then jacked up safe. The outside stay was then removed.
Two large pitch pine beams were placed across the wheel pit area, one over the centre of the wheel and another one about 7 feet away. Two cross girders were spanned across these two beams forming an adjustable lifting area. Using two sets of chain blocks, the wheel was lifted clear of the pit. Then transferring the weight block to block, moving the blocks and cross girders around, the wheel was turned at right angles and manoeuvred until it leaned up against the dam wall and made safe.
The square wheel shaft made of cast iron is 16 feet long and the journals were badly fitted. If I could have borrowed two large lathe headstocks, one for each end, I would have machined the journals in situ, but the cam and shaft together weigh 7 tons and I couldn't get hold of any headstocks large enough to take the cam end, so the shaft and cam had to be separated and the shaft removed from the site for machining.
The end of the shaft where the cam fits is approximately 18 inches square. The hole in the cam is approximately 21. 5 inches square. There are two long keys about 21 inches long on each corner of the shaft. These keys are tapered, and some are driven in from one side of the cam, and some from the other. The tapered side of the key is about 1. 75 inches thick in the centre of the taper. Between these keys it is filled with oak, with iron wedges driven in. All this had to be removed by drilling the wood away around the wedges, so releasing them. Finally I was left with just the iron corner keys to be removed. I found out that using a big striking hammer was about as good as hitting a six inch nail with a toffee hammer!
I then started thinking about some of the large engines and hydraulic machinery that I have worked on. A tup was set up using a large shaft with a half coupling on one end, this being useful for handling purposes. The shaft was suspended from above on two ropes like a plank swing. Holding the half coupling, I pulled it back and swung it with great force, guiding it to hit one of the keys. All it did was to send tremors up my arms! Not to be beaten, two large, high tensile bolts were made, one end of each screwed into a thick striking plate which pushed against the small end of the key. (These bolts went either side of the key through the cam). Another plate was at the other end and packed out from the cam to give clearance to the head end of the key. Nuts were tightened up with a flogging spanner, the first blow hit the striking plate fair and square. It moved, and the nut flogged up again, Another blow and it was beaten. Seven to go. Finally, after a few days of this, they were all out and marked up, the cam being packed and wedged up safe, and my right arm, by this time being nearly useless with the shock from swinging the tup. It had to be guided all the way, no letting go.
The collar was then moved out of the way using blocks, followed by the shaft which required a lot of packing and packing, rolling and re-setting, until it was outside the forge, ready for a crane to remove the shaft, wheel and collar out of the way.
The area around the hammer had to be excavated, starting with the inner sole plate for the bearing. This was resting on a timber 5 inches thick, which had been reduced to about half that thickness through the action of hammering. Before all this could be done the cam had to be moved completely clear of the area to be excavated. The cam weighed about 3.5 tons and I had no crane; it was on a rough floor, was approximately 5 feet diameter with five cams sticking out like sore thumbs, as the saying goes!
A length of heavy section steel beam was found with a plate at one end. It must have been used as a column. I pushed the plain end through the square hole of the cam, leaving just enough room between the face of the cam and the plate on the steel beam to get the jack in. The plain end of the beam was on packings, so that the two vertical webs of the steel beam were up against the top of the square hole of the cam. On Jacking the plated end of the beam up, the cam was lifted clear of the ground. I operated the jack placed between the plate and the cam, and the cam slid along the beam as far as it could go. I lowered it down, making it safe, moved the packings and slid the beam through the hole, setting it all up and started again, until it was completely clear of the working area, and packed up.
When I first started to remove the shaft, I found on jacking everything up to remove the bearings that as soon as the shaft was clear, the bearing housing near the cam could be rocked sideways quite easily. I discovered why when I removed the sole plate and the timbers that it rested on.
Beneath this timber was another one, a lot narrower and shorter. It also had rounded corners along the bottom, giving no stability to the shaft. it was held in place by two square pegs, tapered to a point and quite ragged. This narrow timber rested on some more timber which was quite sound and was left in place. Judging by different indentations in this timber, it had been there long before the narrow timber was installed. It could be timber from the original No. 1 hammer. At this level I could see some timbers that lay below the hammer block. These were quite soft and going rotten. The entire area was excavated, right up to the wheel pit stones and exposing the timber that the head post rested on.
At this stage a complete investigation was carried out. The head post was rotten about 2.5 feet below ground level. Some of the wheelpit stones on the side away from the forge had moved into the wheel pit. The timber at the face of the pentrough was rotten (after only ten years). The shuttle operating the mechanism was 8 inches out of alignment. The shuttle was rotten, the bolts having pulled through the wood, was after only ten years.
English Heritage came to look at all this. They told me to splice Greenheart timber into the bottom of the headpost. Both stays on the dam side of the hammer had to have Greenheart spliced to the bottom of them and the sole plate belonging to the wheel bearing. Also the top stones should be removed and the material behind the protruding stones of the pit dug out, then the stones jacked up to their original positions and the gap filled with a weak mix of concrete. The top stones and the sole plate could then be put back.
The head post and the two side stays were spliced. Work was held up because some of the timber purchased for the job had disappeared, and a journey to Liverpool for replacement timber had to be made. Then the pentrough timbers were replaced, the shuttle mechanism was replaced and made in alignment, a new shuttle being fitted and designed so that the bolts going through the wood did not have any operating stress on them to elongate the holes. All the timber used was Greenheart. On measuring up between the slots where the timber fitted in the pentrough face, it was found that the slots were 1.5 inches further apart at the bottom than at the top. Timbers made to go in at the top would be very slack at the bottom. It was discovered that the top two stones had been moved in on the side away from the forge. These had been re-bedded at some time and then filled with concrete. To move them back to where they should be would be a mammoth task. It was decided to deepen the groove on these two stones to make the bottom timbers fit more acceptably.
The wheel bearing sole plate and the top stones were removed. On digging down at the back another wall was discovered in line with the wider section of the pentrough. It was loose stones and muck that was between the two walls, all very wet, with water coming in from the pentrough.
The protruding wheel pit stones were jacked back, weak-mix concrete was poured in and the top stones and sole plate replaced in position, One thing that I did discover was that the hollowed out section near the sole plate was done after the present sole plate was installed, and after the original wooden shaft was replaced by the iron one. The square end of the shaft was made to have something fitted on it, and with the evidence of a hollowed out portion in the stone work below, holes cut out in the surrounding stonework, and with a lot of scrap ends of shafts and other iron work being found in No. 1 tail race, it looks as though a shear was there.
When the shaft came back on the site, patterns were made for the phosphor bronze bearings. On cleaning the wheel ready for painting the uppermost face of it, it was noticed that all the bolts for the sole boards had been chopped off and the bits were still in the holes. They were rusted so fast they could not be punched out. It was winter time and very frosty. The wheel looked a bit weak near these holes so it was decided to drill them out rather than breaking bits of the wheel off. What a job! Eighty rusty bolts to drilled out in freezing conditions.
A shaft was then set up with one bearing resting on the wheel bearing sole plate and one inside the forge. Mounted on this shaft and over the wheel pit was a pulley. Fixed to this pulley was an adjustable piece of wood. By rotating the shaft and moving this wood in or out, and moving the bearing up or down, away or closer to the breast, the true centre line of the wheel shaft could be determined. At the same time the true outside diameter of the wheel fixed. This true centre line was then transferred to datum points for both wheel shaft bearings.
Greenheart timbers, 5 inches by 20 inches had been prepared to go beneath the cam bearing sole plate. By measuring the bearing house base to the centre of the bearing, the thickness of the sole plate, then adding 1.5 inches for the timber packing and working from the new datum points. I found the correct height for these 5 inch thick timbers to be placed.
Thick plastic sheeting was placed over the hammer foundations and concrete was then poured in to the depth at which the 5 inch timbers had to rest. A drain was then constructed running down the forge wall to the wheel, to take away water leaking through the dam wall to the forge. The 5 inch timber was set in place with a sole plate on top. Concrete again was poured to a level where the cams would clear the rotating shaft. Shuttering was set up to form a box to give clearance to the cam and part of the sole plate. Concrete was poured around this and the hammer to the correct level.
The shaft was brought to the area and lowered down by crane on to packings, and transferred by rollers the forge, clear, of the wheel pit, and into the hole of the cam which had already been brought back and set up in the original position
The cam was set up on the shaft with all the original keys driven in tight. The wheel was lowered into the wheel pit and set up on the original packing. The cast iron insert was lowered down and placed on the packings on the outside sole plate. The entire cam and shaft was brought back towards the wheel, with the shaft going through the wheel the required distance.
The new phosphor bronze bearings were fitted in their housings, involving a lot of hammer and chisel work and filing. The cam bearing, weighing 17st., had to be lifted in and out using chain blocks. Both bearings were tried on the shaft, neither would fit. There must have been stresses involved and both had closed in, A few hours scraping rectified this, The cam bearing was left in its housing, round the back of the hammer, and hidden from view and thieves. The wheel bearing was locked up, out of sight, out of mind!
Greenheart timber packings had been purchased to go between the two sole plates and the bearings. These could not be found. A search of all the Greenheart revealed that a lot more had disappeared, including spare paddles for No.2 wheel. This meant another trip to Liverpool. This wood had to be ordered, so. the shaft bearings were set up on temporary packings. The shaft was lowered into its bearings, and a start made on fixing the insert to the shaft, and the wheel to the insert.
Special wedges were used to set up the wheel and insert on the shaft. By adjusting these wedges, rotating the wheel and measuring from datum points, the perimeter of the wheel was set up (plus or minus 1/16 of an inch in both directions). Oak pieces 3 inches wide were made and driven in between the different parts. Gradually the wedges were removed and the entire area between shaft and insert and insert and wheel, was filled in with oak. The shaft was rotated again and the wheel was still true both ways. Iron wedges were driven into this oak from both sides to tighten it all up, with the wheel being turned and checked, 178 wedges were driven in altogether.
Forty wooden starts were fitted into the holes round the perimeter of the wheel. Forty sole boards made from Greenheart were fitted between these starts using a jig set up to make them all in alignment. The forty paddles were fitted, once again using the same jig. The stays were made of mild steel and galvanised. These were then fitted. Bearing tops were made and fitted, to keep the dust that is constantly blowing around the forge, out of the bearings. The new outside diagonal stay was fitted and lead flashing fitted at the bottom to protect it. All the timber work was treated, the head post cracks were filled in with mastic after treating, to prevent water from the wheel rotting it further.
I just hope, after all this work, that the wheel and hammer are looked after, timber and metal work treated, idiots kept away from it, as well as the sun and the elements. Looked after it should last for years.
(The Cutting Edge - No. 10 - 1994)
Return to Magazine & Journal Articles Contents Page