| | Stray Current Corrosion in Electrified Rail Systems:Transit Operator Interviews (Site not responding. Last check: 2007-11-03) |
 | | Most of the running rails are set on conventional wood sleepers with ballast, but some newer parts of the system use a concrete trackbed (tie in pocket), or a grout slab or wood tie over a high-resilience neoprene pad to damp vibration and insulate the track further from earth. |
 | | While most of the running rails are secured by conventional spikes to wood ties on ballast or concrete, NYCTA has an ongoing program to use insulated clip-type fasteners to secure the rails to the ties, and to replace sections of rail with a welded rail. |
 | | Corrosion of rail spikes is attributed to corruption of the ballast with soil and water wash, which lowers the rail-to-earth resistance, thereby allowing current from the return rails to discharge to the spike and then earth, corroding the spike. |
| www.iti.northwestern.edu /projects/stray2_int.html (4765 words) |