Tadman wrote:I'm about done with the "outlier fleet" line of logic. Look at any major commuter agency and you'll find they have outlier fleets. MNCR has a catenary outlier fleet, a Brookville outlier fleet, and WOH outlier fleet maintained by NJT. Metra has their electric outlier fleet. Boston T has different rolling stock on each line. SEPTA has an outlier fleet of random motors. Why it would be out of order for Maryland to have an outlier fleet of motors maintained by Amtrak is beyond me. It's pretty normal to have an outlier fleet.
Some things to point out:
1) MNR's fleet of 405 M-8s is no outlier fleet by any means. Even compared to the 336 M-7 + 142 M-3 fleet for the Hudson and Harlem lines. And that's really because the different power systems existed long before MNR came into existence (and because CT outlawed use of 3rd rails in the late 1800s/early 1900s so the NH went with wires instead) their fleets are built to their can't-get-around-it needs.
2) The Brookvilles were built as dual purpose units. They could do switching/MOW/etc. jobs and work in passenger trains up to 5 (?) cars. So there was some sort of fleet consolidation with that order.
3) With the WOH fleet the key words are
maintained by NJT. Plus those fleets are a mix of new and still-in-good-condition locos that went out for rebuild. Those Pascack Valley and Port Jervis trains are more or less NJT trains with MNR paint. Heck, those MNR units can be seen on Morris & Essex trains.
4) Again, the Metra Electric service was inherited from its predecessors and tearing down the catenary and running diesels would be simply pointless so alas Metra has a fleet of over 200 electric MUs. Even for a system the size of Metra that is otherwise diesel 200 isn't small.
5) Boston has different rolling stock for each line because -from what I know and can tell- each line has it's different set of specifications and restrictions that date to over 100 years ago. Those tunnels were initally built essentially for -literally- streetcars. Even an "extended Blue Line car without pantographs" for the Orange Line I think ran into design problems due to OL restrictions, etc.
The NYC subway system OTOH had/has 2 types of subway: the IRT and the BMT/IND. The only reasons for the different rolling stock used -aside from the obvious- is that 2 or 3 generations of cars are used at the same time and only so many cars of one exact designation were bought in one or 2 swoops.
6) At the time of purchase nobody was building straight catenary EMUs that could meet SEPTA's requirements. They certainly weren't going to buy any MNR/CDOT M-4s. SEPTA had piggybacked it's order onto an existing order from Amtrak and MARC and at the same time who
wasn't Bombardier building coaches for? MNR, CDOT, NJT, MBTA..
So why not MARC? Well for starters in comparison to the other carriers in the NE and elsewhere, MARC's operation is small by major-city-in-the-NE standards. The Boston-Lynn-Salem-Beverly segment of the MBTA Newburyport/Rockport line has an equal amount of commuter rail traffic on weekdays as MARC does between DC and Baltimore. And to Perryville it's only 6-7 trains each way. Seems that for MARC there would need to be more of a compelling reason to use electrics when they can simply swap diesel sets between lines and save money by not needing to pay Amtrak utility fees.
Very same could be said for the MBTA with the Providence Line. Which btw has an equal or greater amount of commuter rail traffic between Canton Jct. and Forest Hills (where the Needham Line factors in) in 100-125 mph territory as well. And for those CR runs to/from Providence they're traversing in 150 mph territory with only 2 tracks most of the way!