Track Design
Vehicle Systems Design
Manufacturing
Track Renewals
Electrification Testing
Electrification Design and Construction
Overhead Line and Track Renewals
 

The meeting as described here give an insight into the planning that takes place with regards to track renewals and maintenance.

1.0 PPM

This is known as a Periodic engineering Possessions Meeting (PPM). This is held once a month between Networ Rail and the current maintainer for the zone/area. The idea of the meeting is to discuss the type of possessions planned for the following four weeks. A possesion is the term used for stopping trains so that work can be carried out. There are two main types of possessions:

Disruptive possession - this is where train services are delayed or cancelled due to a possession.

Non-disruptive possession - this is where no services are delayed or cancelled due to the possession

In the meeting, as possessions are discussed, the rules of the route are referred to all the time. This is a large document that indicates the times when work can be carried out on the tracks without disruption to train services. So, therefore, the reason for referring to the rules of the route was to see if possessions clash or conform to the times indicated. To understand the reasoning between train paths and engineering works, it is best to look at an example.

Let us consider a planned posession. Looking at the diagram below gives a good indication to the particulars of this case. Due to the possession, there would only be one line open; the down slow (DS). Most of the work is to be carried out on one side of the set of points. Therefore would it not be possible to change the limits of the possession and then run trains on the up fast (UF) and onto the up slow (US)? These type of questions and issues are discussed in a PPM meeting.

Since all possessions and engineering work is planned months in advance, this meeting is the last opportunity to find any conflicts between train movements and engineering works. Within these six months, other contractors may come forward and request permission to make use of planned possessions for other work. At this meeting it is decided whether the request for other works can be granted or not. If we take another example, this can be clarified further.

At a PPM meeting, some Train Protection Warning System (TPWS) work is declined because this would clash with Overhead Line work. The contractor installing the TPWS has requested to be allowed on site at a certain possession. Due to safety and planning reasons, they may be declined.

2.0 PDR

This is a Plan, Do, Review (PDR) meeting. This meeting is held between the Network Rail and the maintainer. The items for discussion are any problems in the area, how they can be rectified and if there are any plans for the future. This is mainly maintenance orientated but also includes how trains and services are, or can be, effected.

Looking at some of causes of train delays in the period (a period basically being one month) helps to identify possible solutions as to how minutes of delay can be reduced. For example, dry switches can cause many delays; this being because points will not operate if the slides are dry.

The main objective of the meeting is to allocate actions to the necessary people, for the applicable jobs or tasks.

3.0 Strategy Planning

A strategy planing meeting is held between different departments within Network Rail.

For example, a strategy planning meeting may be held between signalling Design and Construction, and the maintainer.

The meeting is concerning the Permanent way works in Doncaster. There was a large Switch & Crossing (S&C) renewal being planned there, and the aim of the meeting was to account for every possibility. People from Doncaster signal box were also present to ensure that all predicted train paths were viable.

Several aspects were discussed in this meeting.

Corus wanted to do some work while the renewal was taking place. They wanted to continue building a bridge over the railway, but since they would be using cranes, they were declined. This is for safety reasons. People would be below.

Other aspects that were discussed included the limits of the possession and train movements. For example, what would happen if the last train out of Doncaster on the Friday night was running late? Would this interfere with the possession?

Also, would any other possessions on the zone interfere with on track plant movement. Would a tamper coming from Scotland be detained by a possession in York, for example?

Track circuits were also discussed. This is because when a crossing is removed, signals think that the track circuit is occupied and the signal would remain on red. Re-wiring this so that the signal is green can be done, and is known as 'Frigging'.