Reminder: What are MARC Heat Orders?

Passengers on the Brunswick and Camden Lines often see messages during the spring and summer informing them that there are “heat orders” in effect. CSX Transportation, the owner of the Brunswick and Camden Lines, reduces the maximum speed of passenger trains by 20mph (but not under 40mph) under one or both of the following conditions:

• Consistent ambient temperatures of 85 degrees or greater
• A 25 degree swing in temperatures either warmer or colder in a 24-hour period.

Criteria for heat orders are more stringently implemented when trackwork has recently taken place. Newly-installed rail and ties are more likely to shift in high heat and fluctuating temperature conditions. An example of a sunkink can be viewed by clicking here.

Typically, heat orders cause delays of 5-15 minutes. The less stops that a train makes and thus the more time a train spends operating a maximum authorized speed (such as Brunswick Line train 875 or Camden Line train 852), the greater the impact the heat orders will have on maintaining schedules.
 
In addition, CSX dispatches track inspectors to check the rails during these conditions. This requires one of two tracks to be out of service and may cause additional delays.

Our colleagues at the Virginia Railway Express have written an extensive explanation of heat orders, which can be found on their website.

Heat orders do not take effect on the Penn Line until temperatures reach 95 or 100 degrees, and these restrictions relate primarily to the overhead electric wires. Amtrak’s Northeast Corridor is a heavily-engineered, high speed railroad and much less prone to sun kinks because there is much more frequent, high-speed service, which discourages sun kinks from forming. Also, the Camden and Brunswick Lines have many more curves than the Penn Line does, limiting engineers’ ability to see track defects. It is important to note that this does not mean that CSX tracks are unsafe—CSX maintains its tracks in compliance with all Federal Railroad Administration regulations.


Source:
http://mta.maryland.gov/advisories/what-are-heat-orders