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Quainton News archive - Quainton News No. 37 - Winter 1978 / 9
The Hitchin Turntable - Roy Miller
We had kept our eyes on the Hitchin turntable for some time because it was one of the very last railway turntables in Southern England, and being vacuum operated and within reasonable distance of Quainton it was especially attractive. Enquiries as to when it would be removed or disposed of revealed nothing, electrification and new track layout of the Hitchin yard came and went, still the table remained. We knew it still had its uses; one was the turning of the older type of Travelling Post Office coaches which have offset corridor connections. Again, some of the older mechanized PW equipment has to be turned, and there was the snow plough, a most imposing "wedge type" single ended unit built onto an old steam loco chassis. Much of its latter days, even in mid-summer, were spent sitting on our turntable awaiting the call of duty, ready to charge the nearest snow drift in whichever direction it should happen to be.
Then one day in December 1977 out of the blue, a tender document arrived inviting offers for "our" turntable; somewhere within the deeper regions of BR a decision had been made, and presumably the same administration had made special arrangements with the weather people that it would no longer snow south of Peterborough.
There then followed the usual soul searching and shaking of piggy banks within our Society. The Executive decided that this should be given priority funding, which unfortunately in itself does not make any money but does authorize our Treasurer to shake the piggies a little harder. Some time ago we had heard that the Science Museum would consider giving a grant towards the preservation of unique and historically interesting pieces of equipment. What else is a turntable? It was worth a try! An application was made and acknowledged by the anticipated guarded reply. Further telephone calls revealed that there was more than a possibility that it would take time for all the enquiries to be made and we ourselves would be "investigated". Fine! But we only had 14 days to get the tender into BR. It was at this stage that we decided that we would, if necessary, go it alone. In the event we did not have to, because soon after our tender had been accepted, the Science Museum came up trumps with a 50% grant-in-aid towards the purchase, transport and preparation for storage.
Now came the problems of transport. During the move of Wightwick Hall the transport contractor, Mike Lawrence of Highbridge, mentioned that he had built two special road units for the transport of a turntable for the West Somerset Railway. As this had been delayed it was agreed that the transport of our turntable would be a "trial run" and Mike offered a slightly reduced quotation to "test" his equipment.
By railway standards a turntable is not a very heavy piece of equipment but it does comprise twin beams which are riveted together and so must be lifted together. A moment's further reflection will confirm that a 60ft turntable revolves in a 60ft diameter hole and the nearest point that a crane can get to the centre of gravity for a central lift is 30ft. The use of two cranes, one at each end, was ruled out due to the configuration of the yard. The picture illustrates this point. At a 30ft radius the lift of the table from the pit to the special road bogies would need a very big crane.
At an early stage a "heavy gang" from our Loco Department had worked at Hitchin and removed the two bogies from the end of the main table, the vacuum tractor unit and the decking and hand rails . This made the table look much less formidable but still quite a "lump". Superficial measurement of the main beams and an inspired "guestimate" put the weight of the unit as between 15 and 20 tons. A further problem was that BR stipulated we could only have occupation of the yard on a Saturday, which meant that it would not be possible to carry out any rigging work on days prior to removal. It thus became essential to employ a mobile crane with a telescopic jib; fortunately most modern cranes are like this.
Various crane hire contractors were contacted; two took fright having been to have a look, and another insisted upon the removal of tons of chalk around the side of the turntable pit in order to accommodate two cranes. Then along came Mr Hurst of Graystone Plant who said that his company had a 90 ton telescopic crane based at Croydon. If further work could be found for it they would bring it across London, but first he must see the job. A meeting at Hitchin was arranged; his response was immediate: "That weighs 20 tons at least, my 90 ton crane will not be able to pass over all those other railway lines." Perhaps it was my crestfallen look or maybe it was my assurances that we would be able to fill in the railway lines with sleepers until the surface was as smooth as glass, but our new found friend remained on site. Many measurements were taken to establish the centre point of the crane from the point of lift, also the points of stabilization for the outriggers. Works of reference were consulted: "16.9 tons, not a pound more," then pointing to the table, "and that weighs 20 tons." This meant that by placing the crane end on and across the adjacent tracks, the nearest point to the lift across the pit would be 42ft. and at this radius the crane would lift 16.9tons.
We had no reason to doubt Mr Hurst's estimate of the weight. After all, he had probably estimated the weight of more lifts than we had had hot dinners, but we knew a lot was at stake. The use of an even larger crane, if one happened to be in the area, would have been at least £1,000 per day and might not have been acceptable to BR due to rigging up time, etc. Any other methods such as jacking the beams off the centre bearing, (a lift of some 6ft.), would have required a great deal of time and in the end would almost certainly be even more expensive.
There was nothing for it but to prove the beams weighed less than 16.9 tons! Peter Clarke and I went to Hitchin on Easter Saturday armed with tapes, rules, calipers and calculators, and spent the whole day calculating the weight down to the last rivet. The two lengths of flat bottom track along the top of the beams, together with their fastenings, amounted to almost exactly 2 tons. These could be removed quite easily, but everything else was riveted including the large cast central bearing. The station buffet provided the venue for the final "tot up" of all the weights, and we calculated that if the rails were removed the remaining lift would be 16.4 tons. A slight sigh of relief, but this only allowed 0.5 ton for lifting tackle, lifting beams and friction that might be encountered in removing the table from its centre bearing.
Mr Hurst was a little sceptical but said, "All right, but the crane is fitted with a weighing device and if the overload bell rings I am taking no chances with a £250,000 crane." A very reasonable price of £450 a day was agreed, but the cautionary note added, "If it's more than 16.9 tons you still pay."
The temptation to go back and have another measure and calculation was great but resisted, and lifting day was fixed for 3rd June. Mike Lawrence travelled up with his road tractor and bogies; on the Friday Fountain's 40ft. flat bed lorry was loaded with 200 of our best sleepers (having convinced Neville Royce, PW Chairman, that there really was no alternative). The air compressor, paving breaker, gas cutting gear and other miscellaneous equipment, was also put on board. The crane left Croydon in the early hours of Saturday morning and with a police escort travelled through London to the end of the A1(M). Here another escort took over and conducted it to the station yard. By the time it arrived the Quainton "heavy gang" were unloading sleepers and packing out on either side of the bend in the station yard roadway. Little effort was required here and the crane safely negotiated all its 24 wheels (2 axles single wheeled, both steerable in the front, and 5 axles each double wheeled at the rear) across the narrow roadway.
Then started the task of packing out the 3 sets of tracks over which the crane had to pass to reach the turntable. Very soon the 200 sleepers were used up, together with a few additional ones borrowed from BR; the last 50ft. or so were laid in front of the multi-wheeled monster by removing some of those over which it has passed.
Eventually the crane was in position to the satisfaction of Mr Hurst who had come along to supervise his crane (and perhaps to ensure it did not lift "our" 20 tons), and the nail biting began. An advantage of such a large telescopic crane was the height of the lift which enabled long slings to be used and avoided the necessity of a spreading beam. We thus had our full 16.9 or perhaps 16.8 tons, allowing for the slings and chains, etc. Slowly the chains tightened, accompanied by a throbbing of diesel engines from within the monster; at first nothing happened, then a ringing of bells from the crane cab - it was then that suicide was contemplated or the proverbial hole in the ground was looked for; had we got the weight wrong? However, one of the lads noticed that one end of the table did begin to lift but not the other. There was hope! - it should have been evenly balanced. A careful examination revealed that one end was caught by ¼ inch under one of the exit rail castings, and a few deft strokes with the "hot spanner" (gas cutting torch) soon corrected this.
Again the monster flexed its muscles and this time the table slowly began to lift. Very gently the beams were lifted off the centre bearing until at about 6ft. lift the table was freely suspended. With a gulp we returned our hearts to their rightful places and your Secretary's skin returned its colour from a deep red to its customary dirty white. A quick look at the scale in the crane cab could not be resisted; it registered 16.6 tons - heavy stuff this Great Northern plant.
The rest was comparatively uneventful; the table was placed down beside the road bogies and the crane used to load the lorry with the turntable bogies, vacuum tractor and all the other bits and pieces. The sleepers were again placed under the wheels of the monster which took up its position for a second lift of the table onto the road bogies. While this was going on the heavy gang work with our pneumatic drill, breaking out the concrete surrounding the central bearing part. This proved thinner than anticipated, and with the help of jacks and wedges, the part was prized clear. The monster did not even "rev" its engines to lift this out, although working at a much greater arc, and then carefully placed the part and bearing bracket onto the lorry.
The police escort arrived and Mike Lawrence and load set off for Quainton. Eventually the sleepers were also loaded onto the lorry by a very tired "heavy gang", 200 seemed like 2,000; there was just room for everything. Another police escort arrived and we said goodbye to the monster who departed for another railway job, this time some bridge work for BR at Luton.
Next day Mike and his lads jacked the table off its road bogies and onto a bed of sleepers where it is now. The lorry was unloaded and the tractor unit and bearing part unloaded by our own crane.
We now have a turntable which will eventually form an important part of our schemes for the up yard. The Science Museum have helped us to save this and are to pay 50% towards the cost of painting it for storage until we can install it. If you were unable to take part in its removal, we still need volunteers to clean and paint it now it is at Quainton, so that it will be ready to continue its duties once again.
The table is a Ransom & Rapier No. 8560, tractor unit is No. T67, and it was built at Ipswich, date at present unknown.
Text © Quainton Railway Society / Photographs © Quainton Railway Society or referenced photographer
Page Updated: 17 November 2017