Manufacturers of Authentic Reproductions of Historical Railway Components in 3½", 5", 7¼" & 10¼" Gauge Specialising in Vacuum Brakes & Trackwork
PNP Railways Buying Guide to Track Work in 3½", 5", 7¼" & 10¼" Gauge
"Embrace the Charm of Full-Size Railways in Miniature with PNP Railways Track Work"
Bring your railway dreams to life with our modern and robust track system that effortlessly recreates full-size railway charm. PNP Railways offers a modern and robust track system, featuring easy-to-assemble parts that closely resemble their full-size counterparts.
To help you navigate through the process, we have prepared a comprehensive buying guide that covers all aspects of the PNP Railways track work range.
Scale & Gauge: In the context of miniature railways, gauges such as 3½", 5", 7¼", and 10¼” are scaled-down versions of the gauges used in full-size railways. The most widely used gauge in full-size railways is the standard gauge, which measures 4ft 8½in (1,435mm).
Additionally, narrow gauge railways are characterized by tracks that are spaced closer together than standard gauge railways. This closer spacing results in a narrower gauge. The term "narrow gauge" is specifically used to describe railways with tracks that have a reduced width, allowing for more compact and agile operations.
We use the term narrow gauge to describe rolling stock and locomotives which are running on the same gauge as standard scale but are built to a larger scale and are usually from an industrial heritage.
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What do I use to create a vacuum?You will need either a vacuum pump or an ejector. For electric or internal combustion-powered locomotives, you will require a vacuum pump fitted to a train to evacuate the atmospheric pressure from the train pipe, reservoirs, and brake cylinders to keep the brakes off. It is usually controlled by the driver's brake valve. For creating a vacuum on steam locomotives, you will need an ejector. The ejector consists of a series of cones inside a tube. Steam can pass through the cones so that a vacuum is created in the main body and thus in the brake pipe to which it is connected. A vacuum pump can also be used instead of the ejector.
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Why is it important to limit the vacuum in the system?If the reservoir vacuum is ever higher than the vacuum achievable by the pump or ejector, the brakes will stay on and not come off.
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What do I use for the brakepipe?The vacuum brake system is controlled through a brake pipe (The train pipe) connected to a brake valve in the driver's cab. Each vehicle in the train should have at least one brake cylinder and vacuum reservoir. The train pipe can be a flexible PVC hose that runs the length of the train. It is connected between vehicles, which can be uncoupled when the locomotive and rolling stock separate. When separated the loss of vacuum will allow air at atmospheric pressure to apply the brakes, making the vehicles fail-safe. Releasing the vacuum in the reservoir side of the actuator with the release valve allows atmospheric pressure on both sides of the diaphragm, thus releasing the brakes.
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How do I limit the amount of vacuum in the system?If your steam locomotive has been fitted with an ejector, fitting a vacuum limiting valve will allow you to set the highest limit of vacuum used in the system. This is usually 12" -15” of mercury, shown as Hg units on the vacuum gauge. An electric pump has a vacuum switch that can be set to the required vacuum level.
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What is the difference between the standard brake kit and kit with trunnion mounting?The only difference between the kits is the way that the actuators can be mounted. The standard kit has a stud extending from the rear cover and the other with two bearings mounted at its mid-point. If space is at a premium, then the trunnion version is the better option. The kits are very easy to assemble, and no machining is required.
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What are the brake blocks made from?All brake blocks are plastic injection moulded in a grade of nylon which is filled with glass beads to a level of 40%. The beads are very small and provide the braking medium with the plastic acting as the carrier. The plastic brake blocks bed into the wheels and remove traces of dirt and aluminum. They will also not attach to the wheels with rust.
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What components do I need to fit vacuum brakes?There are of course many different types of locomotives and rolling stock so there is no generic answer. The solution shown below is based on a narrow-gauge Romulus hauling two eight-wheeled wagons. On the loco, all wheels are braked whilst on the wagons just the rear four-wheel bogie is braked.
7¼" Narrow Gauge
Heavy-duty sleeper, specifically designed to support the weight of larger locomotives and rolling stock in 7¼" narrow gauge or 7¼" & 5" narrow gauge. Ideal for well used club tracks and private railways.
7¼" & 5" Narrow Gauge
Heavy-duty sleeper, specifically designed to support the weight of larger locomotives and rolling stock in 7¼" narrow gauge or 7¼" & 5" narrow gauge. Ideal for well used club tracks and private railways.