OLE Structures and support assemblies

What structure is this?

Single Track Cantilever

What is a single track cantilever used for?

2 track railway

What is a single track cantilever designed to support?

1 OLE wire run over 1 track

What are the advantages of single track cantilever

Cheap, easy to construct and adjust

What do cantilevers do?

Support the registration arm that hangs the contact wire

What structure is this?

Double cantilever

Where is a double cantilever used for?

At crossovers and overlaps

What are double cantilevers designed to support?

2 OLE wire runs over 1 track

What is this?

A double cantilever

Is the double cantilever illustrate the principle of mechanically independent registration (MIR)?

Yes

What is meant by MIR in the context of a cantilever?

Each wire run has a support and registration which is independent on any other

Why is MIR an important attribute to have?

In the event of a dewirement or a wire run being damaged, other wire runs shouldn’t be impacted

What structure is this?

Back-to-Back Cantilever

When is a back-to-back cantilever used?

Where there is sufficient clearance between two tracks

What does back-to-back cantilever support?

2 wire runs over two tracks

What advantage does a back-to-back cantilever have over a pair of single cantilevers?

They require less materials

What structure is this?

2 Track Cantilever (TTC)

Where is a TTC used?

When it isn’t possible to install single cantilevers from each side of the track or use a back-to-back cantilever.

Why do TTCs have larger foundations?

To resist the overturning moment at the base of the mast

What is this?

A headspan

What is a headspan used for?

Supporting many wire runs over multiple tracks

Why would headspans be used?

They are the least visually intrusive OLE structure and cheaper compared to portals

What structure is this?

Two track headspan