Until now, there were only a limited number of ways to measure the height and stagger; each can be grouped into one of three categories. Each method, though capable of obtaining the data, differs quite significantly in TIME, COST, and indeed the SAFETY of the men.

Wooden/Glass fibre Crucifix, Dummy Pantograph
Certainly every railway contractor has one or used them in the past. Depending on the actual user they are quite reliable and accurate, but very tedious and slow. The `recording mechanism’, pen & paper equally slow. (& Indecipherable)

Optical devices, Laser light (static), or similar
Quite popular in the UK and Europe, though can suffer from “a subjective view point. In some cases, a tallperson peering into the viewfinder perceives a different `number’ to a shorter person. Bright sunlight, rain,and fog render them less than desirable.

Laser/& video measuring system (train mounted)
The first real attempt to bring H & S measurements into the 21st Century, Fully computerised recording of data, very accurate. Can measure at up to 100mph and more. Some are better than others are, naturally.However, they are very expensive to own and operate. Setup and calibration can take a very long time indeed and they are notoriously difficult to move from point (A) to point (B) at short notice.

In today's high cost; and perhaps volatile maintenance program, cost effective methods are constantly sought to stem the upward spiralling costs.

Continue >>