Cannonball Friday, September 3, 2021, at Seaford

Eleven coaches.

I thought they double-head the power on The Cannonball????

BSB and TBW: The LIRR limit for a single DE/DM30 is six C3 cars.
Any train that operates with seven or more C3 cars is double-headed with DE/DM30s on both ends.
All C3 trains regardless of length that operate into Penn Station must run with two DM30s.
Two R/T from Port Jefferson and two R/T from Speonk weekdays are two DM30s with eight C3 cars each.
The one Oyster Bay through weekday round trip is four or five C3 cars with the two required DM30s.
Any train with C3 equipment has to operate with either a DE/DM30 or a cab car on both ends...That explains
running the two-car Ronkonkoma-Greenport "scoot" with two DE30s when cab cars are in short supply.
This should answer the question on when two DE/DM30s are assigned to C3 trains...

BSB: The prime reason for the use of two DM30s on Penn Station C3 trains are the long third rail gaps around
Penn Station and Jamaica's interlockings. The DM30s must operate in E mode through the East River tunnels
and into the now-covered and built-over West Side Yard...MACTRAXX

Thanks to Mactraxx for the full answer. Once or twice in the 1940's Dad brought me to Jamaica to see DD-1s arrive with long trains. I presume gaps were a problem even then. I recall the DD-1s clanking away, but memory of the steam locomotive backing up fails me. And memory is tricky.

MACTRAXX wrote: ↑Sat Sep 04, 2021 8:41 pm BSB and TBW: The LIRR limit for a single DE/DM30 is six C3 cars.

Is the limit of 6 C3 cars based on horsepower/traction limits or on the limits of HEP current draw?

Has the 2021 Cannonball operated via the Babylon branch, or by the mainline and Central Branch, between Jamaica and Babylon?

Mr. Deasy:
1-I believe that both the HEP limit and tractive effort for one DE/DM30 is six C3 cars.
2-From videos and trainspotters the Friday Cannonball (Train #2798) runs over the Babylon Branch.
From what I remember express trains make better time on the Babylon Branch than running over the
Main Line/Central Branch route running as the Cannonball does nonstop Penn Station to Westhampton...
MACTRAXX