Framingham / Worcester Destressing Project

Is this related to the destressing? If Track 1 is out of service, that would explain why - the Track 2 platform at the other Wellesley stations can be reached without crossing the tracks.

Starting Wednesday: Wellesley Hills Station will be temporarily closed on Wednesday, June 17, through Friday, June 19, from 9:00 am to 3:30 pm due to construction. Shuttle bus service will be provided from Wellesley Square to Wellesley Hills.
Customers are encouraged to use either Wellesley Square or Wellesley Farms Stations during the out of service period.
Shuttle bus service will be provided from Wellesley Square to Wellesley Hills.

Affected routes:
Framingham/Worcester Line

Last Updated: 6/16/2015 2:14:21 PM

The EGE wrote:Is this related to the destressing? If Track 1 is out of service, that would explain why - the Track 2 platform at the other Wellesley stations can be reached without crossing the tracks.

I'm guessing it is. I think you're backwards with tracks...destressing through Wellesley is only on Track 2. Track 2 is the track closest to the parking lots at Wellesley Hills and West Natick.

So I think I agree with your assumption - if track 2 is fouled by destressing operations within the station, passengers can't cross over to track 1. Maybe more importantly, they probably don't want pax on the platform adjacent to destressing construction. So perhaps they block off access to the entire platform - preventing access to the walkway to track 1.

I haven't seen many pictures of the destressing activities. Would have thought someone would have hunted it down.

Cross-posted in the 2015 delay thread, but that post will soon get lost in the hundreds of pages in that thread.

I did a little data monitoring and compilation project this afternoon to get more information about the Framingham-Worcester heat restriction delays. Results posted on my blog:

http://dbperry.weebly.com/" onclick="window.open(this.href);return false;

Breaking news! More rail destressing announced / released / funded. I put all the details on my blog.

http://dbperry.weebly.com/blog/rail-des ... ons-update" onclick="window.open(this.href);return false;

Dave -

nice work on the blog! I am not sure if this is related, but there is new rail that is on the right away next to the track between ashland and westborough (and perhaps further?). It's been sitting there a while. I assume they are going to install it but I don't know when. Presumably as part of the installation process the rail will be heat stressed (or whatever the installation technique is).

harshaw wrote:Dave -

nice work on the blog! I am not sure if this is related, but there is new rail that is on the right away next to the track between ashland and westborough (and perhaps further?). It's been sitting there a while. I assume they are going to install it but I don't know when. Presumably as part of the installation process the rail will be heat stressed (or whatever the installation technique is).

The scope of work for the contract covering track 1 between Framingham and Worcester is actually rail replacement, not destressing of existing rail. So yes, the rail you're looking at is the 'rail destressing' project materials. Work is due to be complete by end of the year. 160,000 feet of new rail in that contract! And yes, rail installation includes heating the rail to a rail neutral temperature of 105.

Why 105? I'm not that familiar with the engineering details of laying welded rail, so that sounds like a high value for a neutral temperature here in New England.

That's about the highest temperature you'll ever seen in New England (Worcester's record since 1892 is 102, Boston's is 104) so perhaps it's to ensure it'll never go too high above the neutral temperature? (You can get rather higher than the ambient air temperature inside the rail due to direct solar heating). Colder temperatures will pull the rail taught, but unless it actually breaks (which should be detected by the track circuits) it won't deform much.

From page 48 of "Track Buckling Prevention: Theory, Safety, Concepts, and Applications," Federal Railway Administration, March 2013:

Rail Neutral Temperature Frequency
CWR installation temperature is typically set within a desired range established in the railroad’s procedures and is typically between 90 °F and 110 °F, depending on the geographic location. This installation temperature is the rail initial neutral temperature. However, as research has shown [12, 14], the neutral temperature does not stay at the rail installation temperature and can decrease to lower values, as low as 50 °F in some cases. These reductions generally result from rail and track movements (creep, curve breathing, track settlement) and track maintenance activities.

The Rail Safety Advisory Committee on CWR Standards has adopted a "RNT reduction factor of 30 F" as the standard value to use when evaluating long-term RNT in the context of resistance to buckling (and the calculation of temperature limits for speed restrictions).

This webinar presents the case for an enhanced calculation of speed restriction temperature, using RNT, the RNT reduction factor, and an assumed buckling strength temperature increase based on track condition. Note that on page 5, there is a reference to a 'conventional' application of a speed restriction at temperatures from 10 to 20 degrees above initial RNT (as opposed to the more complicated formula described on page 8). This presentation takes some time to wade through and understand, but it is pretty interesting.
http://www.lbfoster-salientsystems.com/ ... -19-13.pdf" onclick="window.open(this.href);return false;

So, an initial RNT of 105 derates to 75. Assuming the track quality is strong (100 F factor) - especially after the current construction efforts - the enhanced formula in this presentation would produce a speed restriction temperature of 155 F (100-20+75). Note that is RAIL temperature, and the current industry standard is that rail temperature = ambient temp + 30 F. So a rail speed restriction temp of 155 = ambient temp of 125 F. If you assume only an 'average' track condition (80 F factor), then the ambient speed restriction factor drops to 105 F ambient. Fun with math to go from a RNT of 105 right back to an ambient speed restriction temp of 105. Funny how the formula works that way. It certainly supports the conjecture from "the EGE" that they are aiming for a high enough temperature that exceeds reasonable New England ambient temperatures.

I'm sure they are using some kind of formula to calculate RNT - everything I have seen indicates that the CWR-SAFE software is in widespread use. The contract documents for the project indicate a target RNT of 105.

I have no idea how the MBTA is applying these calculations and factors, but clearly a higher RNT results in a better safety factor for mitigating the potential for buckling.

Boston records in recent decades anyway, are at the airport which is next to the ocean, probably understating the highest temp by a bit. Lowest likely temp would be about -20F with -10F occurring every few years near Worcester.

Boston's lowest low since 1892 is -18, Worcester's is -24. So you're spot-on with that estimate.

Photos of the rail replacement at Framingham station over the 9/12 to 9/13 weekend are posted to my blog: http://dbperry.weebly.com/blog/rail-replacement-project" onclick="window.open(this.href);return false;

IIRC, all eb T trains operate at Restricted speed into the Framingham station as they face a stop aspect at CP-21 just before the Concord St crossing, where gates remain up until T conductor turns key to activate gates upon departure. OTOH, the eb Lake Shore Ltd generally gets a clear aspect at CP-21 meaning Concord St gates are down when 448 cruises to a stop for its typically short station dwell. I wonder if selected morning rush hour T trains might one day get signal treatment similar to 448 at CP-21 in order to expedite in-bound schedules? Perhaps full length High Level Platforms will be required to ensure shortest station dwell time?

Framingham wouldn't be a difficult place to do full-highs, fortunately. Just pull a freight bypass on the dirt patch behind the station for clearance access to the Framingham Secondary.

johnpbarlow wrote:IIRC, all eb T trains operate at Restricted speed into the Framingham station as they face a stop aspect at CP-21 just before the Concord St crossing, where gates remain up until T conductor turns key to activate gates upon departure. OTOH, the eb Lake Shore Ltd generally gets a clear aspect at CP-21 meaning Concord St gates are down when 448 cruises to a stop for its typically short station dwell. I wonder if selected morning rush hour T trains might one day get signal treatment similar to 448 at CP-21 in order to expedite in-bound schedules? Perhaps full length High Level Platforms will be required to ensure shortest station dwell time?

Our dwell times in the station are a lot longer than Amtrak's 448...IIRC, they discharge psgr's only and are on the move fairly quickly. But you are correct, Worcester Mainline TD does have the availability to put a CLEAR aspect at CP 21 for EB moves. As I assume you are a frequent ride, you may well know, our dwell times in the stations are in the area of 3-4 mins depending on the train...Framingham hates that we tie up Concord street as much as we do