I started off in 1999 using plastic Ratio N gauge signal kits consisting of square tapered section posts, these look great and are easy to assemble and operate mechanically, Ratio also provide a signal control kit for operating their range of signal kits (which I must say I have not used myself) but I found the fine plastic signal posts had a tendency to bend during operation, In my view, this spoiled the effect and after a few months of use the signal posts became weakened and began to bend. One starter signal finally broke off across the arm spindle hole in the post, this is probably due to accidental damage weakening the plastic as there were other plastic signals still working well after 2 years use.

During the summer of 2002 I changed all the plastic signalling parts for whitemetal cast P&D Marsh posts, brackets & dolls retaining some of the Ratio plastic signal arms for the mainline signals as these are closer to scale length than the cast whitemetal arms which would be put to better use on yards and sidings. The whitemetal signal posts did indeed provide a stronger alternative to the plastic posts. These were used without handrails, cranks or balance levers and were operated by fine steel wires connected vertically to the signal arms through holes in the baseboards at the base of each signal post. I was not entirely happy with the overall look or method of operation. I was fiddling with home made cranks but did not get time to fit them to the signal posts before the 2002 PDMRS exhibition, the layout was exhibited with the cast whitemetal posts and arms operated with fine steel wire in copper tubes from the rear mounted operating shelf on the layout.

Img:NS1 2mm scale etched brass working cranks on base of post.

Img:NS2 2mm scale etched brass lattice signalpost from BHE.

Img:NS3 New brass lattice post located ahead of the cast whitemetal post it will replace.

At the Poole & District MRS exhibition (10th NOV 2002) I purchased a 2mm scale etched brass version of the excellent 4mm D&S lattice signal post & signal parts etches from BHEnterprises. These etches provide parts to make two complete signal posts with planked platforms, cranks, balance levers & weights, arms, lamp brackets and even tiny etched brass washers. I had partially assembled two signal posts, one short lattice post to carry the up main and up loop starters but this was completely destroyed by my ever helpfull 3 year old daughter who also has a great interest in trains but can be a bit too inquisitive sometimes. The large lattice post shown here had the planked platform broken off and the supporting frames damaged, this one is repairable, the up home/starter wasn't so lucky and was consigned to the scrap pile. Once repaired the large post will carry the Down Main Home/Starter & Distant signals, Down Loop starter and a single short arm (or maybe an elevated disc type shunt signal) for the old shed line. All signals on the layout will be replaced with etched lattice posts in the near future. I am now experimenting with various methods of fixing and pivoting the fine cranks for reliable operation.

The vertical dropper rods on model semaphore signals can be electrically operated and integrated into an electrical interlocking system very easily. Shown here is a Tortoise `Slow Motion Switch Machine' fitted below the baseboard. Here it is used mounted on its side, the operating rod would normally protrude through a hole in the baseboard to operate points directly but they have a multitude of other uses. The small round weight is attached to the bottom end of the signal dropper rod which is held down by gravity onto the moving bar on the Tortoise motor unit, this guards against the signal arm becoming stuck in the raised position. By arranging the connection from the top of the signal dropper rod to the signal arm so that gravity pulls the signal arm to the danger aspect. This is not the cheapest way of operating semaphores but has to be one of the easiest. I would suggest this method as a good place to start for those of You installing working semaphores for the first time, Once you have your main signnals operating it's a good time to have a go at a truly mechanical system on a less used signal.

A compensator is a clever yet very simple mechanical device that consists of two offset cranks with a fixed linkage between them, the compensator ensures the rodding runs are not adversely affected by changes in temperature. It is a simple fact of physics that metal expands when heated and contracts when cooled, this effect is only very slight on short lengths but a rodding run of say 200 yards long, can change considerably in length from the sub-zero temperatures experienced in winter to the relatively high temperatures experience during the summer months. If the rodding was fixed from end to end without a compensator, the rodding could be setup and operate perfectly during the day but at night the drop in ambient temperature would cause shrinkage of the rodding which would pull itself tight, this could easily make the rodding shorter by enough to stop it being able to operate the controlled mechanisms correctly. Compensators are fitted at the mid-point of rodding runs so they act equally on each half of the rodding negating the effects of expansion or contraction due to the change in temperature. There are some situations that will allow the use of normal cranks to perform the role of the compensator. An important point to remember is that half of any run of point rodding should be in tension (pull) and the other half in compression (push) at any one time with the compensator fitted at the mid point. There are certain circumstances where more than one compensator will be used to equalise long rodding runs, this requires the run to be broken down into sections, each section being calculated to have equal tension and compression within itself making an equalised run which will be linked onto the next section. Each sub-section of the overall run will be individually balanced and will have either its own compensator or a series of cranks acting as a compensation device about its mid point. By forming a long run with several smaller balanced sections the overall run will also be balanced. It is worthy of note that the proportion of effort wasted due to friction increases proportionally to the increase in length of the rodding run as the physical weight and number of supports in the run also increase requiring a greater force to be exerted on the operating linkeages to achieve the required movement.

This is a partially assembled 2mm scale LNER lattice signalpost with operating 90 degree cranks fitted to brackets at base of post. The cranks are temorarily held in place with a single strand of fine wire prior to painting. Once painted the post will be fitted to the Stoneybridge West layout. The post will carry the semaphore arms for the Down main home/starter, Distant and Down loop starter signals. There will also be "shunting disc" signal for the adjacent down yard headshunt.

BH Enterprises provide these 2mm scale etched brass versions of the excellent 4mm scale D&S lattice signal post & signal parts etches. These etches provide very fine 2mm scale parts etched from a sheet of 8 thou (0.2mm thick) brass to make two complete signal posts with planked platforms, cranks, balance levers & weights, arms, lamp brackets and even a supply of tiny etched brass washers. I had partially assembled two signal posts, one short lattice post to carry the up main and up loop starters but this was completely destroyed by my ever helpfull 3 year old daughter who also has a great interest in trains but can be a bit too inquisitive sometimes. The large lattice post shown here had the planked platform broken off and the supporting frames damaged, this one is repairable, the up home/starter wasn't so lucky and was consigned to the scrap pile. Once repaired the large post will carry the Down Main Home/Starter & Distant signals, Down Loop starter and a single short arm (or maybe an elevated disc type shunt signal) for the old shed line. All signals on the Stoneybridge West layout will be replaced with etched lattice posts in the near future. I am now experimenting with various methods of fixing and pivoting the fine cranks for operation by strands of fine wire under a constant tension.