SEPTA Cancels CRRC multi level order (Was:SEPTA to get multi-level railroad coaches)

R36 Combine Coach wrote: ↑Thu May 02, 2024 4:14 am Why the trend away from single units? Single units have been featured in the SEPTA fleet since the Pioneer III
and going back to the PRR MP54 and Reading MUs in 1915 and 1931 respectively.

SEPTA is leaning toward consists of 2, 4, or 6-car trains when possible, so singles will not be needed.

Nasadowsk wrote: ↑Thu May 02, 2024 11:20 am Remember, it’s not just being at 100 mph, it’s getting there fast enough, and staying there long enough for it to make a difference, that justifies it.

That's what I suspected; thanks for confirming. Many years ago I read that a similar analysis was behind the PRR's decision to go with 80 or 90 mph locos on certain routes versus 100.

I don’t see a safety case. You crash at 80 or 100, it’s gonna suck either way.

True but there are levels of suckiness, hah! Kinetic energy increases with the square of velocity; going from 80 to 100 increases KE by a factor of (5/4)², or about 56%.

"SEPTA is considering reducing the operating speed of the Silverliner Six fleet to 80 mph from 100 mph."
JeffK: SEPTA MU car speeds between 80 and 100 MPH were always confined to the three Amtrak-owned routes.
Other examples are between Wilmington and Claymont, Levittown and Trenton and west of Paoli -
with the exception of the curve at Atglen.
Express and Limited trains can reach over 80 MPH on certain segments of track along with some deadhead
equipment moves...

"Governing" the Silverliner Six MU cars to 80 MPH will be the equivalent of how NJT modified the Arrow MU cars...
Both NJDOT Arrow MU car types as built were capable of 100 MPH originally...
MACTRAXX

MACTRAXX wrote: ↑Fri May 03, 2024 6:22 am "SEPTA is considering reducing the operating speed of the Silverliner Six fleet to 80 mph from 100 mph."
JeffK: SEPTA MU car speeds between 80 and 100 MPH were always confined to the three Amtrak-owned routes.
Other examples are between Wilmington and Claymont, Levittown and Trenton and west of Paoli -
with the exception of the curve at Atglen.
Express and Limited trains can reach over 80 MPH on certain segments of track along with some deadhead
equipment moves...

"Governing" the Silverliner Six MU cars to 80 MPH will be the equivalent of how NJT modified the Arrow MU cars...
Both NJDOT Arrow MU car types as built were capable of 100 MPH originally...
MACTRAXX

Per FRA regs, for whatever maximum speed the cars will be set to run, they have to be capable of running a certain percentage over that speed in testing. So they'll actually be capable of speeds in the mid-90's.

In all fairness to NJT, the 80mph max for the Arrow III's was not by choice. They were supposed to return from rebuild as 100mph cars. Blame that on poorly designed traction motor cooling systems.

The Arrow IIIs came back as 80mph cars because…

*shakes magic 8 ball*

ExCon90 wrote: ↑Wed May 01, 2024 8:20 pm

Silverliner II wrote: ↑Tue Apr 30, 2024 9:16 pm Cynwyd caters more so to the reverse commuter. The last time I rode the Cynwyd Line, it was in April of 2019 to do a video ride of the line. I rode the second outbound trip of the morning, and the train left 30th Street with perhaps 1/3 a car full, so perhaps around 30 people. Most getting off at Bala.

Very likely household help. I didn't think of that, but for many years there was regular ridership westbound in the morning on the Paoli line; maybe there still is.

Gotta watch that autocorrect -- it changed Paoli to Palo when it thought I wasn't looking. I had to go back and correct it twice before it accepted the correction and then changed it to Palo again when I was typing this sentence.

Decent amount of reverse commuting going on especially to Paoli with Vanguard. SEPTA brought back the express reverse train in the morning and afternoon.

What is the submission deadline for the new rail cars RFP?

"Governing" the Silverliner Six MU cars to 80 MPH will be the equivalent of how NJT modified the Arrow MU cars...
Both NJDOT Arrow MU car types as built were capable of 100 MPH originally...
MACTRAXX
[/quote]

Given 2/3 "reimagining regional rail" concepts featured some degree of express service, and taking into account the track and signaling improvements Amtrak is conducting on the Keystone Corridor, this is coming off like a setup backwards. As it stands, at least 90mph can be reliably sustained between stations on the Trenton, Wilmington, and Paoli/Thorndale between Malvern and Exton. Not to mention the easily hit 100mph stretches of the Trenton and Newark lines.

Speaking anecdotally, I've found the acceleration on the silverliner v's to be far stronger than that of LIRR, Metro North, or Metra Electric equipment limited to 80mph. And this is disregarding the silverliner iv beating pull the ACS-64's have with a 5 car set.

TLDR: why did they even mention the 80mph vmax/does better acceleration really necessitate lower vmax?

Thanks y'all,
Frequent Wayne to NYC commuter that dreams of an all day limited-stop train to Trenton.