Question

Assessment 8.0: Drainage

Produce a drawing to explain the drainage requirements for a section of plain line track. Identify the gradients and the installation of drainage.

1. Describe 3 types of drains used in common practice within the UK rail industry?

2. Explain how water drains from the track bed, and the effect of ballast on track drainage, and identify the contribution that inappropriate or contaminated ballast has on the drainage of the track bed, and the creation of wet beds?

3. Explain the process of ballast deterioration and identify the salient causes of ballast deterioration?

Would prefer this in text as I can't understand the handwriting on here.

Answer 1

Drawing for drainage requirement for a plain rail track

Three types of drains commonly used in UK Rail industry are-

1. Side or Cess drain - These are surface drains located at the formation level at the side of the tracks, to remove water that has percolated through the ballast and is flowing.along the capping layer towards the outside of the track formation. These drains run parallel to the track and are usually open jointed glazed earthenware, galvanized corrugated steel or perforated PVC or polypropylene. They are most frequently found in cuttings where water running off the formation cannot freely drain away.

2. Catch drains - These may also be called top drains or surface drains. The purpose of catch drains is to intercept overland flow or runoff before it reaches the track and causes damage to the track or related structures, such as cuttings or embankments.For example, catch drains are generally located on the uphill side of cutting to catch water flowing down the hill and remove it prior to reaching the cutting. If this water was allowed to flow over the cutting face it may cause excessive erosion and subsequent silting up of cess drains.

3. Mitre drains -

Mitre drains are connected to cess, catch, and surface drains to remove water or to provide an escape for water from these drains. Mitre drains should be provided at regular intervals to remove the water before it slows down and starts to deposit any sediment that it may be carrying. As the grade of the drain decreases (i.e.it becomes flattered) mitre drains should be provided at closer