Southern Electric Group 4Cor unit 3142 Preservation Report 4

4 COR Preservation Report 1999

Work on the front has been almost completed. The gangway has been refitted and the whole front end repainted in yellow in keeping with our ultimate ambition of running once more on the main line. In Figure 1 is a sketch of the layout of the junction boxes which are such a feature of the front ends of southern EMU’s. Apologies to those who are familiar with these, but I dare say that there are others who, like myself until recently, have often wondered what they all did.

There two jumper leads which emerge from under the centre of the drivers window and headcode box respectively. That on the driver’s side is for the 750 volt power line so that power may if necessary flow from one unit to the next, and the other is the 12 way control lead. When the unit is not connected to a further unit the jumper leads plug into dummy receptacles towards the outer corners of the car. When the unit is operating in multiple it must connect to a mirror image of itself.

Concentrating first on the power side. The main power input from the rail (after the fuse) goes to the inner (power) receptacle on the headcode side. The power jumper from the other unit may then plug into this receptacle. Alternatively power may be shared by connecting the power jumper from the driver’s side on our unit to the power receptacle on the headcode side of the other unit. The control signals are made common to both units in a similar way, the control jumper on one connected to the receptacle on the other. Possibly connections may often have been made on both sides, but the system seems to have been designed so that units could be coupled/uncoupled from one side only. All of this is probably of only academic interest now, as multiple operation is probably very unlikely but not completely impossible as there are still four COR power cars in existence (our three and one at the NRM). Unfortunately our power receptacle has been damaged during restoration, and this is the only part on the front end not yet replaced. It may be possible to repair by welding alternatively a replacement may have to be borrowed from one of the other power cars.

Moving on now to restoration of the offside (i.e. headcode side). This was in a very similar state to the nearside with panels rusted right through in many places. The teak main bearer (the large bottom beam of the wooden frame which forms the side) was also split repeatedly lengthways by rusted steel bolts. Repairs to the wooden main bearer have taken the same form as on the previous side, with the outer 3 inches or so which were split, being cut away and a patch made from iroko which is the only affordable hardwood available. This patch is then held in place by galvanised coach screws and cascamite wood glue. The repaired beam is then bolted back to the uprights of the frame using new angle brackets and coach bolts. These brackets and the bolts are also galvanised to reduce the rate at which they will rust, probably nothing will stop rusting completely, the bolts are also greased before insertion. The original bolts were almost certainly not so treated, even so they have lasted 60 years.

On the nearside the lower panels were completely replaced and the upper panels above and between the windows had patches welded in where necessary. This has produced a very good result however we have gone about the second side in rather different way. Firstly the cost of a complete set of new panels was rather off putting. Secondly we had relied on someone else doing the welding for us, this is a bit inconvenient also it means that anything requiring welding must be taken away to be worked on, this is often not a problem but some of the panels e.g. those on the back end of the coach are rather too big to carry in a car.

Having seen the value of being able to weld panels, I decide to equip myself with a small DIY type of MIG (Metal Inert Gas) welder, the type most often used for repairing/customising cars. This device produces a low voltage (about 30 volts), high current (up to 100 amps on this model) DC arc. The molten metal “glue” is formed from steel wire which is fed to the torch from a spool driven by a motor. The welded area is flooded during the welding operation by an inert gas—carbon dioxide (sorry about the greenhouse effect), which prevents oxidisation during welding.

After some practice on pieces of scrap (we have plenty of this), I tried out the machine first on the offside driver’s door. The bottom 6 inches or so of this were rotted completely away. There was now no need to pop rivet the replacement patch in place ready to take for welding by the garage, it was simply held by clamps and tack welded in a few places. Welded seams were then used to fill the gaps in between these tacks. The result after grinding and filling seemed as good as the earlier repairs and so all the remaining upper panels on this side which require patching have been treated in a similar way. Some of the upper panels which were too badly rusted to repair have been completely replaced by cutting a section from an old scrap lower panel. in many ways this is easier than doing several patches with all the associated grinding and filling.

We wished to replace the lower panels on the offside by new ones. On the nearside these were cut and drilled and had an overlap added on one edge to form the seam, by a professional sheet metal company. To avoid the cost of this we experimented with the panel nearest the back of the car by buying a plain sheet of zinc plated steel (zintec) cut to the right size and drilling the fixing holes using the original piece as a template. This was 16 gauge thickness which is in fact rather thicker than the original, heavier and more difficult to bend. However the result was just as good as the panels on the other side. The second and third panels from the back were considered to be capable of repair and patched in the same way as the upper panels. We had done this before on the guards compartment on the nearside, the result is not as good as a new panel but still probably better than the sides of more modern all welded stock (CIG’s etc.).

For the remainder of the offside we have again bought plain sheets cut to size, and drilled the fixing holes ourselves. This time we have used the slightly thinner 18 gauge metal, which is just a shade thinner than the original. The extra complication with these other panels is that an overlap must be folded on one edge. This overlap and the method of folding it is best explained by reference to Figure 2. The final result being hammered into shape instead of folded on a press are not as smooth, but given that a joining plate is then fitted over the top of the seam the finished job is perfectly adequate.

These new sheets certainly look better than the patched ones and also are easier to make. This is partly because of the time taken to cut new patches and weld them in, but also using new sheets avoids the lengthy process of stripping off 60 years of paint. As an aside this paint is over ½mm thick compared to about 1.4 mm for the steel panel. The various colours the unit carried can be seen starting with a hard grey filler, olive green, malachite (or other lighter Southern railway greens) BR green, blue and further green added in preservation. A hot air gun seems to be the best way of removing it, but it is almost impossible to get off all the filler at the first attempt.

There are seven panels on the passenger saloon side of the coach and another on the side of the guards compartment. The lower side of the guards compartment is very similar to the panels on the side of the passenger saloons and is being replaced with a new sheet. However the top of the guards compartment has no window therefore a rather larger sheet is required than for the lower panel, this is approx. 1.1m high compared to 0.9m for all the lower panels. It so happens that standard zintec sheets are 2m by 1m. This means that this top panel has to be patched, as luck would have it both top and bottom of the panel were badly rusted consequently a 2½ inch strip was cut off each edge, and a 5 inch strip welded onto the top, the whole sheet therefore moving down 2½ inches, which is the pitch of the fixing holes so these should in theory still line up, we hope. At the time of writing six of the lower panels are now back in place. The seventh and both guards panels are still being finished off also some woodwork repair still remains to be done.

From earlier articles you may remember my description of the difficulty involved in removing rusted bolts from the wooden frame. This problem still causes a good deal of sweat and bad language to be expended, but the secret seems to be just persistence. Hammering the bolt from one end then the other will eventually break up the rust as it is after all quite brittle, there is always a great sense of relief when eventually it is seen to move just slightly. The worst problems with bolts are those that run horizontally through the main bearer to bolt into brackets holding the main bearer to the cross members, the main bearer it must be remembered is 9 inches thick. There are only about four each side. These are only present to hold the frame together until it is bolted to the solebars, however they are in general rusted quite badly this side seeming rather worse than the nearside. Sometimes as mentioned before, we have cut a thread and fitted a nut on the end, those that are too badly rusted have to be driven out, often it is necessary to drill a series of holes around the outside of them firSt

In parallel with this work on the side, we are also removing and repairing the panels on the rear of the car. At first it was hoped that the panels could be patched in position but eventually we decided to remove panels, gangway and all the fittings (brake gear junction boxes etc.). The details of this will be left until a future article.

As an interesting diversion from work on body sides, we have recently spent a few days rescuing as much electrical gear as possible from one of the Brighton Belle power cars which has now been moved to Stewarts Lane depot ready for conversion to a hauled coach as part of the VSOE Pullman set. It is hoped that this equipment will provide valuable spares for us in the long term. In return for this favour, the group has donated two of the old stencil type headcode boxes to fit on the cars after conversion. The Belle units were fitted with roller blind type headcodes before withdrawal, and these have since disappeared. It seems that eventually one of these ex-Brighton Belle power cars will be situated at either end of the VSOE rake.

While at Stewarts one of the staff kindly showed us the VSOE Pullmans, some of these were of course originally Brighton Belle stock. However on a personal note it was one which was only ever steam hauled that caught my attention. This was “phoenix” which under its original name “Rainbow” was badly damaged by fire at Micheldever in 1936 while part of a Southampton boat train. It was renamed after rebuilding in 1952. The interesting thing about it from my point of view was that I had previously heard the story of this Pullman on fire from my father who was one of the Winchester fire men who tried unsuccessfully to put the fire out. It’s a small world.

Just to conclude, we are now quite close to getting the outside of the body rebuilt, it has been two years in the process, but we believe time very well spent Our next target will be the roof, we had considered using the original canvas and paint technique but now plan to use a more modern plastic tarpaulin which should remain water proof for longer. Another job we must soon tackle is to replace much if not all of the glass in the windows, several window panes having been broken during removal. We have to decide what type of glass to use, the originals were probably plate glass this is probably not well thought of in modern safety terms. More modern post war vehicles use armour plate glass, but possibly only safety glass as used on cars will be adequate for main line running.