All of the posts on this topic are here.
If you haven't read anything about heat restrictions and want an explanation of what this is all about, read the first post here.
Today's post is kind of fun...instead of just re-posting news and explanations that are posted elsewhere, I get to break some news that hasn't yet been reported anywhere!
The breaking news is that on August 12, 2015, the MBTA expanded the scope of the rail destressing project to include track 1 from Boston to Framingham. Prior to this contract modification, as I have previously explained, this section of track was not scheduled to have rail destressing performed on it, meaning heat restrictions would never have been eliminated for trains on that track. Technical details of the additional scope are contained in this "Field Memo 5."
This is good news, since it now means that ALL of the tracks used for ALL outbound trains (not just rush hour) have rail destressing projects either completed or underway.
The bad news is that this work probably won't be finished in time to make a difference this summer.
The MBTA has now updated their website and published a great map that confirms my earlier speculation about the extent of the rail destressing project. This updated FAQ document also confirms our thoughts on the project extents.
The map really helps to explain the project in a visual way. Most outbound rush hour trains travel on track 2 (the orange line on the map) from Boston to Framingham, and then on track 1 (the green and blue line on the map) from Framingham to Worcester. Since both the orange and blue represents areas where rail destressing is complete, you can see where trains are allowed to operate at "track speed."
To help explain the effect of the various aspects of the rail destressing project, I expanded the table that I created for an earlier post. This table shows the track that each train usually travels on versus the status of the rail destressing project.
1) Where the rail destressing project is NOT complete (in other words, any yellow or red on the table), the max speed of any train during a heat restriction is 30 mph.
2) Weston is the location of the "CP 11" set of switches that allows trains to change tracks. It is next to the golf course, just west of Route 128, and between the Wellesley Farms and Auburndale stations.
3) Framingham is a station stop where all trains stop, so rail destressing doesn't really matter there, since all trains are going slow anyway. I'm not sure if they are even doing rail destressing in that area.
4) "N-A" indicates that those trains don't operate there (i.e. originate or terminate in Framingham).
To use the table, simply find your train and read down to follow what tracks it normally operates on. Then you can understand if you are likely to encounter heat restrictions (now or in the future).
For example, if you are riding on train P527 (the 'express' that departs South Station at 5:00 PM), you can expect to operate at 'track speed' (60 mph in most places) all the way to Framingham (on track 2, the green squares in the table). After Framingham, you're normally on track 1 to Worcester - but at reduced speed to Westboro (the yellow square in the table). Make sense?
Other important notes:
1) Even if 'your' train shouldn't experience reduced speeds due to heat restrictions according to my table, other delayed trains (especially inbounds) may affect the timing of meets and routing at switches, meaning your train might be delayed even though the rail has been 'destressed' on the section you are operating on. For example, inbound P526 or P528 operating at a reduced speed for the entire length of its transit (at least now) can delay outbound trains by 'getting in the way' (especially at the single track through Allston).
2) As recently reported, the schedule for all commuter rail lines will change on November 1, 2015. Therefore my table above may not accurately represent what the conditions will be for the summer of 2016, when all of the 'yellow squares' would presumably turn to 'green squares' (since the current projects are due to be completed in 2015).
3) I have simplified the "Worcester to Westboro" section for track 1. A close inspection of the project map shows that on track 1 there are sections that are complete (blue line) and sections that are not complete (green line) within that stretch. For simplicity, I'm calling it all complete, but you will probably experience a reduction to 30 mph between Grafton and Worcester on heat restriction days over the next few weeks. I guess I'm cutting the MBTA some slack by calling it complete for the table above.
The MBTA actually published the project map back in July and I saved it. Note that it doesn't indicate today's breaking news - the addition of rail destressing from Boston to Framingham on track 1. On this July map, that section is still dashed peach - awaiting scheduling of the project.
So kudos to the MBTA for releasing the money to do more rail destressing!
It will be interesting to see if they can find the money to do the remaining section of track (track 2 from Framingham to Worcester) that is the last piece of the rail destressing puzzle.