Friday, October 27, 2017

Specialized equipment helps MTA fight leaf slime

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Long Island Rail Road applies a traction gel during the fall to help increase traction of rail wheels. Long Island Rail Road applies a traction gel during the fall to help increase traction of rail wheels. Metropolitan Transportation Authority / Patrick Cashin

Metropolitan Transportation Authority (MTA) is utilizing a fleet of specialized equipment and increased vegetation control methods to help combat a potentially hazardous by-product of autumn: leaf slime.


When leaves fall on tracks and are then crushed and compacted by wheels, a gelatinous, slime-like substance can occur that reduces the adhesion train wheels have to the rails and can affect a trains stopping distance.

"Anyone who has ever driven a car and tried to brake on a patch of ice knows something of what it feels like for a train engineer who applies the brakes to a train on a patch of rails coated in liquefied leaf residue," said MTA Chairman Joseph Lhota. "As autumn begins we turn our attention to fighting leaves that have fallen on our tracks, but throughout the year we work to combat vegetation along the rails."

MTA's railroads institute slower speeds when slip slide conditions are reported to ensure safety, but crews from the Long Island Rail Road (LIRR), Metro-North Railroad and the Staten Island Railway will also be operating work trains that spray water jets to clear tracks of slimy leaf debris. A specialized Metro-North work train sprays water at high pressure and specially equipped highway/rail trucks use rail scrubbers to remove crushed leaf residue from the tracks. On-board Metro-North diesel passenger trains, "sanders" automatically drop sand onto the tracks to help improve traction and reduce wheel slippage. On the LIRR, a specialized train then applies a traction gel onto the freshly cleared rails that allows train wheels to maintain traction, even in the presence of crushed leaf slime.

The first step to reducing these delays for the LIRR, Metro-North and the Staten Island Railway is to trim or remove trees and vegetation alongside the tracks, either through railroad personnel or by hiring outside trained and licensed vegetation management contractors. About two thirds of the leaf matter that interferes with railroad operations on Long Island comes from invasive species such as ailanthus trees, black locust trees, Norway maples and bamboo. In the region served by Metro-North, the majority of the leaves come from oak, sugar maple and birch trees and sumac.

LIRR alone plans to engage contractors to trim back vegetation along 80 miles of track in 2018 and 94 miles in 2019. Bushes and trees on LIRR property are subject to removal and tree branches extending onto railroad property may be pruned as well.