How many wheels per axle are powered on the Amtrak/PCC Metroliner? Was there a vestibule diaphragm at the Metroliner ends that retracted with sliding side doors if the A ends of the cars were detached?
All four axles on each Metroliner mu car were powered, and there were four dc commutator motors for each car. Each car had its own transformer, rectifiers, and switchgear.
Yes, there were retractible diaphragms.
alloboardHow many wheels per axle are powered on the Amtrak/PCC Metroliner?
In case that was the actual question: two. Even the 'original' Pioneer truck design used rigid axles ... which, as it turned out, were more stable at high speed than independently rotating wheels would have been.
In the Pioneer design, there is one traction motor per axle, but it is longitudinal and drives the axle with gearing. I believe the GSC trucks had nose-suspended motors, although trame-mounted motors would in my opinion have been far more appropriate to high speed. It did not help having commutated motors with carbon brushes when it came time to negotiate even the "improved" track on the PRR/PC 'corridor'...
Back in the day, the assumption was that you wanted to motor every axle to get to high speed, both for reasons of adhesion and adequate power. This was before the adoption of 25kV or higher catenary power and comparatively light vehicle structure (as on the French productilon LGV and production TGV.
Here's a picture with the clamshell nose doors retracted. You can see some of the diaphragm structure inside the opening:
When the former Metroliner cars were rebuilt as cab cars the retractable doors were replaced with fixed diaphragms - some of the cars may have been modified while still im powered Capitolliner service. You can still see evidence of the motor mounts on the cab cars trucks - it's pretty clear that they were conventional nose-suspended motors.
I have the Walther Proto Metroliner. The feature of the clamshell sliding doors were not added. Now here's what I want to do. I need someone to design a special vestibule diaphragm that I can stick on to the A ends. Doing this will make the Metroliners look more prototypical.
I should have added that the B ends had conventional fixed diaphragms. I think the B ends had small hostling controls for independent movement in yards and shops, but i am not certain and unsure whether they survived the major rebuilding. The cars were designed to be used in pairs, back-to-back, but were still independent cars, not married pairs. But occasionally a train did have an odd number of cars, meaning a B end could be coupled to an A end in service.
The cars were well-powered, the individual traction motors being rated at 255 or 300 HP each, for 1020 or 1200 HP per car.
Does the concept of married pairs apply to the Jersey Arrow III's. Can a Jersey Arrow III married pair car with a B end with conventional fixed diaphragms be coupled to an A end Jersey Arrow III car or the double ended Arrow III cars. From what I know, there were no double ended Metroliner cars.
That's allot of horsepower per car! I know off MU cars with about 300 HP. MU's don't need allot of HP's because they pull in groups. Since every Metroliner car was powered, unlike Silverliners and Arrows, it's like a 4 car Metroliner train is like a double headed 4 locomotives with no coaches or freight rolling stock in consist.
See, me old son, you're in the right place!
Oh, and if you like trains under wire slide over to page three of "General Discussion." Mario v has a video posted titled "Trainspotting in Italy." It also "stars" the Orient Express.
Not the US or the NEC, but an interesting video just the same.
alloboardDoes the concept of married pairs apply to the Jersey Arrow III's(?)
The answer is yes and no. There are 200 married pairs (cars 1334-1533), and 30 single units (cars 1304-1333).
1. Remember that Metroliners were designed for 165mph and were heavy cars, possibly the heaviest mus ever.
2. I believe all Arrows and Silverliners were powered, no trailers, except when motors were out of service because of a mishap. Most were married pairs with some single units. Married pairs mean cars can not operate individually. Usually batteries and charging equipment under one car, and compressor(s) in the other. These were much lighter cars, lower top speed, and lower HP motors.
daveklepper 1. Remember that Metroliners were designed for 165mph and were heavy cars, possibly the heaviest mus ever. 2. I believe all Arrows and Silverliners were powered, no trailers, except when motors were out of service because of a mishap. Most were married pairs with some single units. Married pairs mean cars can not operate individually. Usually batteries and charging equipment under one car, and compressor(s) in the other. These were much lighter cars, lower top speed, and lower HP motors.
The Arrow IIIs and Silverliner IVs could creep up over 100. I used to ride a four car set of Silverliner IVs from 30th St. to Marcus Hook every day. Express to Chester. Used to top out in the high 90s to low 100s through Ridley park (they let us ride in the vestibules and the speed indicator was visible and functioning in the trailing cabs).
From a practical standpoint, it would have been better to use the Silverliner/Arrow platform for the Metroliners. They rode better and just a bit more oomph and some better aerodynamics would get them to 110 - 120 mph - which would have been sufficient for a 3 hour schedule.
They also ran okay in the snow - something you couldn't say for the Metroliners.
-Don (Random stuff, mostly about trains - what else? http://blerfblog.blogspot.com/)
Bud did want to use a modified version of the trucks and motors, but the PRR said no. Once the weight was increased for outside-feam, drop equalizer trucks, entirely different motors were required, axle-hung, a poor choice for high-speed. So I essentially agree with you. The Silverliners and Arrows could be modified to run 160mph. Today, with ac non-synchronous motors, no problem.
Weren't the Metroliners originally supposed to have the Pioneer III truck used in the Silverliners, Arrows, and Metropolitans?
I was a mere youth at the time, but I do remember that the Metroliners were already under construction before all of the results from the Silverliner test beds were in. What wound up being delivered to PRR/PC was a fleet of 61 prototype high-speed MU cars that had not been properly de-bugged before being placed in service.
alloboard That's allot of horsepower per car! I know off MU cars with about 300 HP. MU's don't need allot of HP's because they pull in groups. Since every Metroliner car was powered, unlike Silverliners and Arrows, it's like a 4 car Metroliner train is like a double headed 4 locomotives with no coaches or freight rolling stock in consist.
- Paul North.
NorthWest Weren't the Metroliners originally supposed to have the Pioneer III truck used in the Silverliners, Arrows, and Metropolitans?
Thanks, that makes sense. The Pioneer III railcar had longitudally mounted motors, although I forget how they were geared.
NorthWest Thanks, that makes sense. The Pioneer III railcar had longitudally mounted motors, although I forget how they were geared.
All of CTA's post-war equipment also had longitudinally mounted traction motors, two on each truck. They used hypoid gears, similar to an automotive differential, to transfer the rotational motion to the axle.
CSSHEGEWISCH NorthWest Thanks, that makes sense. The Pioneer III railcar had longitudally mounted motors, although I forget how they were geared. All of CTA's post-war equipment also had longitudinally mounted traction motors, two on each truck. They used hypoid gears, similar to an automotive differential, to transfer the rotational motion to the axle.
CTA did build an eperimental version of the CTA-1 truck (used under the 2000 series cars from Pullman-Standard) that had crosswise motors. The CTA-2 truck had some maintenance advantages, but was considered to be harder on the track and passengers. It was used for a time on one or more of the 1-4 and 6127-6130 cars.
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