MBTA's Max Speed?

It is 100% equipment design. EMD engines are rated for 100mph, and if they were pulling a train of Amfleets they'd be allowed to go that fast. HSPs are rated for 90, and all MBTA coaches regardless of type are rated for 80mph. The coaches are limited due to FRA regulations pertaining to weight and braking ability.

I coulda sworn I heard someone say the rotem cars were rated for 90.

Probably not much extra work to certify a coach for 90 vs 80. And Hyundai-Rotem would want to sell similar cars to other systems that want to go faster, and perhaps the MBTA CR will go faster within the life of these cars.

Right from my NORAC book. 11th Edition

Reminds of the Arrows which were downgraded to 80 after their AC traction conversion overhauls, though they could still easily do 100. Running times in timetables had to be modified as such. Rumored that the one powered truck configuration was a reason.

Most commuter lines (except NJT and MARC on the NEC) do not hit over 80.

CSRR, that's an Amtrak employee timetable, not a NORAC rulebook.

jwhite07 wrote: ↑Sat Jan 06, 2024 7:03 pm CSRR, that's an Amtrak employee timetable, not a NORAC rulebook.

OK fine if we're splitting hairs, those pages are located in the System Special Instructions in my NORAC rule book.

It's not splitting hairs. The photo you provided is from an Amtrak employee timetable, not a NORAC rule book. They are two completely separate and distinct documents. Examples of both documents are publicly accessible on the internet, so it is easy to show this -

NORAC rule book:
http://www.cottonvalley.org/safety/NORA ... -01-18.pdf
No specific equipment speed restriction tables to be found anywhere

Amtrak employee timetable:
https://www.multimodalways.org/docs/rai ... 1-352+.pdf <- see page 171 of the PDF and you will find an older version of the table you posted from a prior ETT revision

CSRR573 wrote: ↑Sun Jan 07, 2024 11:12 pm

jwhite07 wrote: ↑Sat Jan 06, 2024 7:03 pm CSRR, that's an Amtrak employee timetable, not a NORAC rulebook.

OK fine if we're splitting hairs, those pages are located in the System Special Instructions in my NORAC rule book.

Mr White is correct. 2 different documents. It is not splitting hairs

all respect Mr CRail, but the HSP's MAS is 103 mph

The K and R cars are capable of steady 90 mph operations, just no one wants to have their signature on the paper work for solid K/R cars running at 90mph. On the "break in tests", we get up to 93 mph. The K and R cars are equipped with both tread and disc brakes, enhancing braking capabilities at high speeds, similar braking apparatus as the current Amfleet cars operated on the Regionals.

The FRA has various standards for track infrastructure and maintenance. Maintenance costs for the standard beyond Class 4 (80mph) probably has diminishing returns, especially for commuter railroads with frequent stops. The only reason why the corridor is maintained to Class 7 (Class 8 in Mansfield) is because Amtrak runs trains through without stopping anywhere besides Route 128 and can benefit from the higher speed. Also keep in mind that up until recently 79mph was a hard limit for trains without PTC (which is moot now as PTC is required and has been installed on everything). Additionally, GP40MCs struggle to get up to 79mph while pulling a train of double deckers before starting to brake for the next stop anyway. Since equipment is assigned to an entire side and not to any particular route, they're not going to make a schedule that they potentially can't keep if they happen to have equipment that can't do the expected speeds; so they make schedules and set limits with this in mind. The timetable speed limits of 79mph are remnants of a combination of all of these things.

MBTA F40PH-2C 1050 wrote: ↑Mon Jan 08, 2024 3:33 pmall respect Mr CRail, but the HSP's MAS is 103 mph

I appreciate the respect, but your very own timetable disagrees with you. HSP-46 speeds Lite, Multiple Lite, and With train are 50, 50, and 90 respectively. I have deduced that this is why ACSES displays 90 in the cab on the corridor when MAS for MBTA equipment is 79mph. Interesting to note is that ACSES displays 80 in the cab in other locations where MAS is 79mph.

CRail wrote: ↑Wed Jan 10, 2024 1:44 am

MBTA F40PH-2C 1050 wrote: ↑Mon Jan 08, 2024 3:33 pmall respect Mr CRail, but the HSP's MAS is 103 mph

I appreciate the respect, but your very own timetable disagrees with you. HSP-46 speeds Lite, Multiple Lite, and With train are 50, 50, and 90 respectively. I have deduced that this is why ACSES displays 90 in the cab on the corridor when MAS for MBTA equipment is 79mph. Interesting to note is that ACSES displays 80 in the cab in other locations where MAS is 79mph.

Sorry for the confusion. The OG question was the HSP's MAS....which is 103 mph per the MBTA Operating Instruction Book. We are restricted to those speeds you provided, by the Keolis S.I. book

As for the "80" vs "79" display, the Worcester ML has this issue, it is just another glitch in the coding that would have cost $$$ to go out and "correct" the transponders in the gauge, they just left it at 80. Should be 79 mph.

As for the 90 mph displayed on the ADU, I was told it was the "C" or "D" speed ratings to comply up and down the Shoreline, I'll inquire into that tomorrow. Doesn't matter today tho, MBTA trains operating over Amtrak territory are considered "B" trains now...yet our ACSES hasn't been updated to "B" speeds ......$$$