It was “traditional” in the 60s that loco manufacturers using the ubiquitous Twin Disc converter ran it on diesel fuel. It saved carrying a separate reservoir, so there was less to build and maintain, and if you took two independent feeds off the fuel tank, and made the engine the higher one, the engine would stop before the converter was starved. But that was then. Fifty years on, and successive legislation has reduced the sulphur content in diesel, indeed, from the beginning of this month the sulphur content in “gas oil” (the red stuff we put in the fuel tank) has to be the same as that of DERV (the clear stuff you pay the extra tax on for the privilege of running your car). The process by which the sulphur is reduced unfortunately impairs the “lubriscosity” of the fuel, in other words, that elusive element that makes it a good lubricant is taken away. Added to that, we have seen converters fail through water in the fuel (as the converter is often below the fuel tank, it ends up finding its way there, especially when operators forget the cardinal rule of keeping the tank half-full at all times) and suffer when various microbes take up residence. Consequently it has become our policy that as Andrew’s locos come through for major TLC, we switch their converters to run on hydraulic oil.
Bev's supercharger (oranged ribbed bit), dynamo behind, oil cooler right foreground and old converter cooler (top right)
In Beverley’s case this primarily requires adding a reservoir tank for the oil and re-routing the suction and return lines to this from the fuel tank, but, as always we made it a touch more complicated, improving the system by incorporating a direct-to-air cooler- which has added 25mm to the overall casing length, and in anticipation of eventually vac-braking, added a pulley to the front of the engine to drive an exhauster, which involved raising the radiator a few inches in order to clear it. When we started all this on Bev, the converter and its associated piping was still full of gas oil and although in the course of re-routing the main converter hoses from old to new coolers, some of it had been drained, we needed the loco over a pit to access the plug in the bottom of the converter which, sadly had been left as a plug when we had the whole power unit out at Middleton a few years ago. Bev was now over a pit and it was my first task to get underneath and drain the converter. Working in a pit is at least easier and more comfortable than crawling about on a filthy concrete floor, but standing in close proximity to a 25 litre drum and funnel and hoping that you have successfully lined it up to the column of fluid that will emerge when the plug comes out is not a comforting feeling. Having reached up through a strategic hole in a frame cross stretcher to release the plug, I chickened out and found that I could – just- reach the plug with my fingers while laying down on the running plate. At such safe distance I drained the fuel out of the converter and afterwards made a generous donation to the fuel tank of the nearby 02 as Andrew had no confidence in me pouring it in Bev’s tank without spilling it down his pristine paintwork. A drain tap will replace the plug for future changes.
The new tank
Next I went back to the front of the cab and set about determining where the tank could go. Neither Mr Hudswell nor Mr Clark considered the possibility of needing to add anything here, so there are a mass of air, coolant and fuel pipes, tacho cables and throttle linkages to miss, and finding a suitable location on one side might not be convenient on the other, but eventually 4 holes were drilled, 4 spacers cut, and the reservoir tank mounted. But plans to test Bev by cranking and maybe starting the engine (I had disconnected the converter charge pump belt in case we did) were thwarted by the discovery that not only were the batteries flat, but that they would take no charge, and sadly that is really our fault for leaving them unattended for so long.
During the week I have had my mind on the 03 so far as control system, etc goes and the first stage of the wiring diagram is now in existence, though it will take a fair few revisions before it incorporates all that we require. Part and parcel is turning the old 5-speed gear change linkage (of which only the cross-shaft and hand levers remain) into a means of operating 3 solenoid valves on the powershift. By the end of the week I had abandoned hours spent over the last few weeks mapping complicated quadrants watched over by perception sensors to traditional cams tracked by limit switches that came from the Jarvis auction lots last year. I also made enquiries with my favourite prop-shaft specialist about a suitable drive shaft to connect the powershift to the final drive, and was rather shocked by a price of £620 +VAT. Anyone out there got an 1810 series shaft they don’t want?
Saturday: Andrew woke up late with a streaming cold and his original plan of heading over to York to deal with Pluto’s reluctant exhauster was abandoned. Instead we eventually made it to Rowsley and while he pottered about firstly on “Libby” and then, after the compressor and riveting gun of the boilersmith made the atmosphere un-conducive, outside in the VBA. I meanwhile, having donned the ear defenders (for no other reason than the shed radio was turned up loud with Tony Blackburn), chopped two lengths of angle and drilled them ready to mount the transmission cooler on the 03 followed by drilling out a piece of 3mm plate to form the top of the new tank on Beverley. Finally the collar that will form part of the brake operating linkage on the Drewry was drilled and tapped to accept a grub screw.
Sunday: Andrew was feeling a little better and had arranged to make a start chopping up some rails he acquired a year or two ago when he had plans of having his own low-loader complete with loco-loading ramp. Today such ambitions have been replaced by the reality of £620 prop-shafts and since the rails are on odd-ball section, they are destined for Mr Booths once they have been cut down to fit a skip.With a crash-course in operating a Geismar rail saw – (Aah, Geismar. Back in my Thomas Hill days we manufactured several maintenance vehicles for Geismar. One was fitted with a hydraulic crane, so carefully balanced that our overhead crane hook picked it up and it stayed perfectly vertical. But it was so heavy that the vehicle springs wouldn’t take the weight. The Geismar resident engineer told us to burn off the crane’s counterbalance and weld the column firmly into the chassis of the vehicle. We protested to no avail and our fabricators set too to burn off a significant lump of steel in convenient pieces. The remains lay for a few weeks on the workshop floor, and somebody chalked them an epitaph – “Mickey Mouse wears a Geismar watch”) – we had cut two or three when we had to break off for a meeting with Peak Rail Joint MDs about future projects. By the time we’d finished we had daylight for a couple more before it was time to call it a day.