What are Heat Restrictions?

Track Northeast Corridor

It's officially the dog days of summer, and record temperatures are being recorded from Death Valley to Delaware.

Aside from the extra AC, the triple-degree heat also means potential heat restrictions along our rails. In a nutshell those are rules that require our trains to slow down when the track temperatures reach a certain level. Once that happens, heat restrictions are issued and our trains reduce their speeds to keep our passengers and crews safe.

With this system, we rely on the temperature of the track instead of the temperature of the air outside. That data is collected at stations along our tracks and ensures we're only issuing heat restrictions when necessary.

7 comments
BCCletts
BCCletts

One way to mitigate heat issue is to soak the track and use the high latent heat of evaporation of water to remove the heat from the trackbed and rails (approx 250,000 calories for every 1 pound of water which evaporates). Works even better when the track is grass covered as vegetation provides natures no-power air conditioning system for all the parks and green spaces in towns and cities. 

Pre-stretching rails on securely ballasted track is the way that the expansion (and potential for track to buckle) is mitigated.

p2lf
p2lf

Does the restriction get lifted at night when temperatures are back into the 90s?

Mike77E9
Mike77E9

What kind of reductions in speed are we looking at? We know CSX likes to reduce entire divisions by 20MPH

Patrick_TheLIRRToday
Patrick_TheLIRRToday

@Mike77E9 Metro-North (the owner of the NRO-NHV segment of track) has different levels of Heat Restrictions that restrict trains to roughly 70 m.p.h. on straight sections of track (down from 90 m.p.h.) and down to as low as 50 m.p.h. on turns.  The Metro-North section suffers from a lot of overhead wire sagging due to the older style overhead wire.

Pan-Am Railways, which owns the track that the Downeaster operates over between Maine and the Massachusetts state line institutes a 40 m.p.h. speed restriction over their territory, which can causes awful delays to the Downeaster.

That's just scratching the surface, all of the individual host railroads have their own way of instituting heat restrictions.

~ Patrick @ The LIRR Today

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