Published on: Wednesday, 1 November 2017
Last updated: Tuesday, 7 November 2017
This autumn, leaves have fallen off trees at a faster rate than last year, but performance is up by about 4% on average across all the branch lines.
Branch lines suffer more with slippery rails during Autumn as they operate through countryside, nature reserves and areas of outstanding natural beauty, where there is naturally much more vegetation.
Falling leaves create mulch that sticks to the track and gets compressed and hardened by train wheels into a Teflon-like layer. This makes the track as slippery as black ice, so train wheels lose grip and in some cases become damaged. The mulch can also cause the electrical circuits on the tracks to fail, which can also cause delays.
Traditionally the first two weeks of November have seen the highest levels of leaf fall so we are just about to head into the most challenging time for performance.
How the industry tackles ‘leaves on the line’
Vegetation clearance
Making sure that as few leaves as possible fall onto the rail gives a good head-start in tackling autumnal problems. Network Rail spent £150K removing trees and bushes close to the line in East Anglia this year.
Railhead Treatment Train
Railhead Treatment Trains, operated by Network Rail, travel around the network jetting leaf mulch off the rails using a high pressure spray. On the Greater Anglia network, these are based at Stowmarket and Broxbourne which go out every day cleaning the rails. Network Rail also uses a specially adapted ‘road to rail’ vehicle called a ‘Sand Rover’ to clean rails in areas that the Railhead Treatment Trains cannot access.
Automatic sanders
All trains are fitted with automatic sanders that can deposit sand onto the rail and as this is crushed between the train wheel and the railhead to increase grip to assist when a train is braking and accelerating
On-train monitoring
Greater Anglia trains are fitted with a real time monitoring system which reports slippery conditions straight to the Control Room. This data is sent directly to a Network Rail manager, called the “Autumn Adhesion Manager”, based in Greater Anglia’s Control Room throughout the season, who then sends teams out to the affected areas to clean the rails by hand. The teams are usually on site within an hour.
Wheel Slide Protection (WSP)
Like ABS on cars, WSP stops train wheels locking when braking so that they do not become damaged in slippery conditions. This is fitted to most of Greater Anglia’s fleet, and for the first time this year has been fitted to nine Class 156 trains which operate on the branch lines. Greater Anglia is already seeing an improvement in performance as a result of this £500K investment.
Wheel Lathe
If train wheels are damaged through slipping on leaf mulch, the train has to be taken out of service to have the wheel repaired on a lathe. Greater Anglia invested in an additional lathe at Crown Point Depot, Norwich, to help speed up repairs. The Class 156s should not need to visit the lathe as often now that they have had WSP fitted, making branch lines services more reliable.
Greater Anglia’s branch lines are:
Colchester – Sudbury
Ipswich – Felixstowe
Ipswich – Lowestoft
Norwich – Great Yarmouth / Lowestoft
Norwich – Cambridge
Norwich – Cromer / Sheringham.