NER class D, LNER class H1 4-4-4T

Our aim of making all the wheels share the load so that the driving wheels can provide as much traction as they are capable of, has been achieved. 

 

With all classes of loco that have the cylinders mounted low and between the front bogie wheels, there's always going to be a problem with the bogie wheels shorting on the cylinders or the cross heads and slide bars.

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One solution is to use a nylon based material for the cylinder end covers.  This cures the front pair of bogie wheels shorting out. If you want to stop the rear pair of bogie wheels shorting out on the cross heads, a solution that partly cures the problem is to use the backing piece from the cross-head as a template and make a one from  Slater,s Plasticard.  If the curves are less than 3 feet radius the rear pair of wheels on the front bogie will still short out on the cylinder slide bars.  A belt and braces solution is to add a small piece of insulating tape to the inside face of the cylinders. We have restricted the radial movement of the front bogie but if you must run tight curves the axial movement will cause you problems.

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The answer to all these problems is to use cylinders made from an insulated material and a motion bracket that's insulated too.  We know how we could do this but the costs involved in doing this is prohibitive for a small manufacturer. We've come up with what we think is a reasonable compromise and used this text to point out the problems that the modeller is likely to encounter.  These are just some of the problems we've encountered and had to find solutions to while designing and producing this chassis.  EM and P4 modeller's won't have this problem if they are running 4 feet radius curves.