Crank Handle Box – Type 2
- The crank handle box is a trackside enclosure that houses and controls the points machine crank handle.
- It provides automatic electrical indication when the crank handle is removed. The box complies with Transnet’s standards.
- The crank handle is secured so that only authorised crews can remove it.
- A special key is required to fit the pad lock, which forms part of the inner cover.
- The cover cannot be closed until the crank handle has been replaced.
- Maintenance personnel enter by opening a separate pad lock, which gives access to all operating parts of the box.
- The crank handle box has two electrical contacts.
- These open when the crank handle is removed and close when it is replaced.
- A set of screw-type terminals provides internal and external connections.
Materials and finishes:
- The box is constructed of robust galvanised and mild steel – stainless steel is available on request.
- The inner case is cast iron to give durability and protection. Installation is simple.
- A support post bolts to a concrete foundation. The crank handle box is virtually maintenance-free.
- The junction box is a multipurpose trackside enclosure designed primarily as a cable termination box for points machines.
- It provides a convenient test and isolation point to facilitate maintenance work.
Mechanical and electrical description:
- The junction box is available in single or double entry versions.
- The underground power feed and detection cables are terminated at clip-on terminals, in the junction box.
- Materials and finishes
- The junction boxes are available in galvanised mild steel or 304 stainless steel.
The support post is normally buried in the ground so that the junction box lid is level with the top of the points machine box lid.
- The apparatus case is a multipurpose trackside enclosure.
- It may house external control equipment for trackside points and signal control.
- It may also house 24-volt DC batteries and chargers.
- A power annex case may also be fixed to the side for power requirements.
Mechanical and electrical description:
- The apparatus case is available in a number of standard sizes, related to the equipment it is intended to house.
- The cases have a swing door at the front and at the back to simplify access for testing.
- Underground cables brought into the case for termination run in conduits.
- Materials and finishes
- The cases are available in galvanised mild steel or 304 stainless steel.
The apparatus cases are supported on concrete legs buried in the ground in accordance with standard installation specifications.
Mechanical Points Indicator:
- The mechanical points indicator is designed to meet the demands for safety and reliability required of railway signalling equipment in a crossing loop situation.
- The points indicator is manufactured by ALSTOM Transport.
- With the exception of on-condition inspection cycles, the mechanism is maintenance free.
- The purpose of this type of indicator is to provide train personnel with a positive indication of the points position to be negotiated by the train.
- The indicator is mounted on a steel cradle fixed to two sleepers.
The points indicator is supplied in two forms:
- two-way points indicator (for crossing loops)
- one-way points indicator (for sidings)
- The points indicator is coupled to the points set via a ground rod configuration and hand tumbler.
- The indicator is split into three sections, namely:
- Base section – housing the detection slides, lever slides and vertical plunger
- Centre section – housing the connecting rods between the mechanism and indicator disc arms making up the distance section between the base and top sections
- Top section – houses and supports the indicator disc arms as well as the cranks for the connecting rods from the base and to the disc arms.
- When the points are operated by the hand tumbler, the indicator lever slide lifts the vertical plunger clear of the detector slides and allows the detector slide to move across as the switches move to the other position.
- When the movement has been completed and the points are properly closed, i.e. switch to stock, the vertical plunger will drop by means of gravity into the respective notch in the detector slide and all-safe indication will be given.
- If the points switch is not properly closed to the stock, i.e. tolerance of 0 – 3 mm, the detector notch will foul with the plunger preventing indication.
- The result will be that both arms will remain in the ‘danger’ position.
- For self-normalising trailable points, the indicator is designed to provide positive indication of the lock of the rail mounted points lock as well as detection of each individual switch to stock position.
- Two-way indicator used at crossing loops
- One-way indicator used at sidings
- The indicator incorporating separate detection slides for each switch that is used in conjunction with the self-normalising trailable cylinder.
Self-Normalising Trailable Cylinder
- The self-normalising cylinder is designed to fulfil the strict requirements for safety and reliability required of railway signalling equipment.
- The trailable cylinder is an ALSTOM Transport design manufactured in South Africa.
- Incorporated in the design is an internal, easily adjustable time delay mechanism whereby the normalising action can be pre-set over a wide range of time settings.
- The trailable cylinder is a hydro mechanical device and requires no electric power.
- The trailable cylinder’s mounting arrangement is on a steel cradle, fixed on two sleepers.
- The cylinder has overall compact dimensions and can be conveniently handled in the field.
Internal time delay mechanism, easily adjustable from 3 seconds to 10 hours.
245mm, giving a minimum points opening of 90mm and a maximum points opening of 210mm.
- Operating from ~36o C to +800 C
- Length 1000mm
- Diameter 140mm
- Weight 90kg
For shunting purposes or opposing train movements, the points can be operated in the conventional manner with a hand tumbler.
- The trailable cylinder is used as the prime mechanism of the points at crossing loops, in conjunction with the rail mounted points lock assemblies and hand tumbler.
- The trailable cylinder can also be used in conjunction with a mechanical points indicator where no electric signalling is available.
- The trailable cylinder’s sequence of operation is as follows, with a train trailing through a points set:
- The open switch is forced closed with the first wheel of the train unlocking the Cl clamp lock and opening the closed blade – at the same time activating the self-normalising trailable cylinder.
- Once the wheel has cleared the blade, the time mechanism begins operating.
- Dependent on the preset time adjustment of the self-normalising trailable cylinder for the complete train set to clear the points, the operation rod of the trailable cylinder retracts slowly, pulling the blades towards the set position.
- At a preset distance from the end of the stroke no resistance is present internally of the cylinder, allowing the operating rod of the cylinder to close and lock the switch to the stock rail and so preparing for the next train movement.
Self-normalising trailable cylinder.