Brian Podmore

This part of the project involved making the wayside ground apparatus. Not cosmetic but functional, and therefore built for strength whilst looking like the real thing. The ground apparatus consisted of two separate parts and how I tackled these is as follows.

Developing and testing the ground apparatus

Using two diagrams from the Hosegood book for the ground framing gave me an insight as to how the structures were built for service in the real world. They showed this was a far cry from the Hornby OO travelling post office set I have. It appears that there were variations across the country, between companies and even how they were sited. In certain circumstances the ground gear would not be all together on one side of the track but be split so that the bags on the wayside collection apparatus were on the down line and the wayside pickup apparatus was on the up line. My choice was to have both together on a fairly short length of straight track on the up line between a road bridge and a tunnel. Even if it all worked it would be quite a challenge to get the job done in the time allowed between exiting the road bridge and entering the tunnel, but more on that in the last episode of this project.

With most of the measurements on Hosegood’s drawings being clearly visible, I was able to begin calculating the other necessary ones to build my version of the wayside ground apparatus.

It appeared that the bases of the wayside pickup apparatus actually rested on two sleepers buried underground (fig 1).

Figure 1.

The bases of the posts were circular and had four bolts holding the arm bases to the sleepers. The lower step legs were at the same level as these sleepers and the whole arrangement was held together by two further sleepers. It was a substantial structure designed to withstand considerable impact as a result of the bags being snatched by the net from the passing coach.

As clearances were somewhat tight on the real apparatus, the string used to steady the bags as shown in fig 1 was to deter the bags from waving about in the slipstream caused by the coach passing and thus allow the net to catch them cleanly. The impact of the net on the bags broke the strings, (I have omitted this detail in my working model). This part of the ground apparatus was the first of the two part set-up required which I began to build once the materials were assembled.

The second part of the ground apparatus, the catching frame and net, was also a substantial piece of work (fig 2).

Figure 2.

Catching two huge leather bags travelling at speeds in excess of 50 mph required sleepers to be used again and be buried in the ground to support the net whose job it was to survive this impact in collecting the bags. A combination of chain and net was used for this process and positioned so as to guide the bags diagonally away from the trackside for eventual collection by the postman. My needs now were clearly identified from the drawings and a collection of parts for it duly took place. What follows is a record of what this meant in terms of construction and even if it didn’t work, it would still be a small diorama adding interest to my railway. But working it would be.

Constructing the pick-up apparatus

Gathering together the materials list, and component parts for the pick-up apparatus took some time. The challenge for me meant understanding the real situation and construction and then interpreting it all down to a scale of 7mm to 1 foot. I used 2mm and 3mm brass pipe for the upper and lower supports of the pick-up apparatus and for the swivel joint I used some low carbon soft steel bearings commonly referred to as catapult ammo balls 9.5mm in diameter. These I drilled through to 3mm to accommodate the brass piping. This was easily achieved using a lathe to drill out each ball, (fig 3).

Figure 3.

The easiest way to drill the correct size hole in the ball was to place it in the lathe chuck and use a drill chuck in the head stock. I used a 2mm drill secured in the chuck so that the drill was only a couple of mm proud. This enabled me to make a countersunk starting hole in the ball. I then extended the drill and drilled into the ball repeating this until I was all the way through. I replaced the 2mm drill with a 3mm drill and drilled that through the ball. The balls were obtained as a pack of 10 from Simply Bearings Ltd for around £2. A simple mock-up of the main component parts of the pickup apparatus to scale is shown in fig 4. The feet were turned on the lathe and are the scale diameter 1ft 8in.

Figure 4.

Adding the wooden framework held it all together and shown here in fig 5 is a simple mock-up of the main component parts of the pickup apparatus to scale. I have now modified the swivel arms so that they have handles as per the prototype, and cut several planks of lime wood sectional timber usually used by model boat builders to act as sleepers to support the whole structure.

Figure 5.

The two ladders are from a signal kit with strengthened sides. I made brackets to secure these ladders underneath the platform and at the base as per the Hosegood drawings. The top half of the piped arms merely sit in the ball bearings and swivel around. They are held at the right height by washers soldered onto the pipes. The small handles on the swivel arms act as a locking device and were subsequently bent down to rest in two slots cut in the back of the balls to allow these levers to sit securely. This stopped them from swivelling when the bags were collected by the passing coaches net.

I adjusted the lengths of the upper arms that protrude towards the coach and gave them bosses as shown in fig 6. I also glued four plastic flutes to the lower arms so that they looked cosmetically the same as the real thing. This almost completes this part of the apparatus.

Figure 6.

Adding the flutes to the lower sections, and cutting limewood sleepers to the correct width, finishing off the ladders with securing strips at the bottom of each meant that the whole thing could now be glued together. Essentially as mentioned before, it had to make up into a strong structure that can take the knocks it will experience in usage.

Fig 7 shows the finished wayside pick-up apparatus, approximated to Hosegood’s drawings. It really is important that everything is rigid and strong enough to withhold impact both to the ground apparatus and the coach apparatus. In reality, the stresses were felt not only on the apparatus but also on the track, so much so that frequent attention had to be given to keeping the track straight alongside this apparatus to avoid accidents.

Figure 7.

Fig 8 shows a close-up of the securing slots described earlier in the ground apparatus. The bar sticking out to the left of the platform which is now cosmetic, would normally be used to steady the bags on the double hanger with string.

Figure 8.

The last parts of the pick-up apparatus, the hanging bracket arms, were created next. Based on available images they looked like horizontal pegs sitting inside a holding bracket onto which the ’thimble’ in the leather straps of the bags was hung. The real post bag strap I believe had a brass thimble in it which slid onto the peg and a clip arrangement hinged over this to hold it in place, (although I think string was also tied round this assembly to do the same job), and stop it dropping off the peg once the bags had been positioned for collection. For my model, it was important for me to keep this part of the apparatus as simple as possible so that a clean snatch of the bags could be achieved by the net. So no clip or string, just the pegs slightly pointing upwards, (fig 9).

Figure 9.

The brass arm and chain arrangement on the coach knocks the bags off these pegs and literally thumps them into the coach holding area. It appears that a single and double bracket was often used so I have created one of each in the apparatus. You can see the mechanism I devised clearly in figure 9. This will make sure that the collection is ‘sweet’ and does not destroy the equipment both on the ground and on the coach, something that did happen in reality!

Constructing the wayside collection apparatus

This was put together as shown in fig 10. I won’t describe a blow by blow stage of building it as you can see clearly that I have constructed it using a combination of brass bars, brass strip, chain and sleepers. The Hosegood diagram contained enough information with dimensions clearly shown to create a 7mm scale model. The wood I used again was lime wood and as stated before is normally found in the company of model boat builders, (info on suppliers at the end of this article). The next job was to sort out the netting.

Figure 10.

There seemed to be many versions of netting used according to various sources on the Internet, but the main purpose of the equipment was for the rope and bar to catch the bags and have them flung into a net which is supported by the sleepers and chain. The metal frame or grid which is closest to the rail side is usually hinged so that it can be folded away from the trackside once the bags have been collected, but I have made mine from scrap brass and it is fixed, (in normal practice the postman would remove the horizontal bar holding it upright and lower the frame to tilt it away from the rail side when not in use). The net is arranged at an angle to the rail side and access to the bags for the postman is on the embankment side of the framing. Looking at the many drawings available, the netting was very coarse, similar to the nets used by quayside cranes to lift crates onto ships. After some thought and several helpful discussions at Telford with various folk last year, hair nets were suggested as a possible solution. So I invested in a couple of types. The equestrian type tended to be thicker and stronger, but alas still too elastic in nature, so I was unsure at this stage on how to proceed. Then while sorting through an electrical box of bits I came across a ‘string’ bag used to hold computer cables and microphones. The makeup of this bag seemed to be ideal. I’ve shown the two types I considered side by side in, fig 11. I’m sure that someone knows of the ideal material.

Figure 11.

I could have sat with whipping twine and created my own nets, looked into the methods of netting technology and knots, but the road to perfection is often a long one. We all choose to stop sometimes before the final destination and use what we have and make the best of it. This is what I decided to do with regard to the netting. With reference to fig 11, the net on the right is the computer one, not woven but it looks like rope netting and is very strong. The one on the left is an equestrian hairnet. Much lighter and strong although in the end it was much too elastic for my purposes and I therefore discarded it in favour of the computer one.

Fitting the netting was not straightforward. Fig 12 shows the initial pattern and then the final positioning of the net. The T- shape cut shown, was a first trial but it needed an extension on one arm as it has to fit a rhomboidal type shape. This was another trial and error situation and when finally acceptable and functional it was then glued in position and finally sewed in place to give extra strength. The corners of the net were also glued and sewn with black thread.

Figure 12.

This completed the two parts of the ground apparatus. All that remained was to make up mailbags, adjust the length of their hangers, and test for clearances.

Construction of the mailbag

I needed heavy mailbags and after deliberating over how to create small leather pouches that were heavy enough to work on the apparatus, I came across the solution which at the time was staring me in the face laying on one of my platforms.

I had several pigeon baskets stacked up in a couple of places. These pigeon baskets were about the right size of a mail bag and because they were made of cast whitemetal were heavy enough, and they look the part as shown in fig 13. It was just necessary to solder a brass hanger into them and paint them.

Figure 13.

Siting the apparatus

To position the ground apparatus in the correct place it was necessary to have several trial runs of the coach, (hand driven in the first instance), with the gear down to adjust access clearances. Once I was happy with this, the ground apparatus was glued into position (fig 14).

Figure 14.

The importance of testing several times is crucial both manually and behind a locomotive at varying speeds. A straight length of track is required. I struggled with that and had to redesign adjacent sidings of my tar works to accommodate enough space not just in length, but depth as well, for the ground apparatus and postman’s hut. Once I was satisfied with the arrangement, I was ready for the next and final stage. As yet, I had not started to organise the control of the coaches net and its traductors to operate in any particular way. The mechanisms were in place as detailed in the first part of this series, but the use of DCC now had to be brought into play. How this was achieved, I will explain in the next instalment.

Figure 15.

Figure 16.

Books

Great Western Railway travelling Post Offices, J.G.Hosegood, 1983, Wild Swan Publications Ltd, ISBN: 0906867169. Pages 12 and 19. 76 pages soft bound

Suppliers

Squires Model and Craft Tools 100 London Road, Bognor Regis, West Sussex. PO21 1DD Tel: 01243 842424. Fax: 01243 842525. sales@squirestools.com

The Model Dockyard, PO BOX 104, Redruth, TR15 9BJ. Tel: 01209 861733. www.model-dockyard.com

Simply Bearings Ltd, Halton House, Greenfold Way, Leigh Business Park, Lancashire, WN7 3XJ. 01942 269837 www.simplybearings.co.uk www.bpodmore.co.uk – search for TPO