4666 has the AML brake system and has a 70 PSI brake pipe setting. When by itself the straight air(equivalent to the independent brake on a regular diesel locomotive) can/will go to the full 70 PSI. As the car will stop on 10-15 PSI, I have never seen it go that high when moving. When not acting as the locomotive (like dead-in-tow for the move), there is a valve that gets opened that puts a 35 PSI safety on the cylinder.

As told to me, the original PRR specs to Brill stated that the car had to be able to pull 2 P-70 coaches at 65 MPH.

When built in 1930 the throttle was mechanical for the gas engine. At some point, I assume in 1941 when the diesel was put in, the throttle was changed to hydraulic. When BR&W made the cab car, the throttle was changed to air. The CNJ car that BR&W used was scrapped back in the late 1990s.

The rollers are Timken.

Back when 4666 moved from NH&I to BR&W, PC did not require a 200 million insurance policy that I have been told NS wants today for a move like that.

4662 is not really a sister, maybe a close cousin. It is a Pullman with a very different power plant. Where 4666 has a pony engine for the 32 volt system with the main engine for 600 volt traction and cooling fans and has full transition - series, parallel,and reduced field; 4662 has 2 smaller engines with only reduced field.

Looking at the passenger end of #4666 I notice there is some sort of MU plugin along with some extra hoses. Is this a recent modification to allow operation with other locomotives or has this always been there since the Pennsy era? I've personally never seen any photos of it running with extra power at hand.

Cameron

Mr. Wolk:
READ EDM's post at the bottom of the previous page, where all is explained.

In the photo, I see a brake pipe, train signal line, main reservoir equalizing line, and an application/release pipe.

All of which make perfect sense, at least to me.

And a C-S coupler! When was that added?

Howard P.

35 pounds for IND is common for the clamp-style brake shoes.

The MU was added by BR&W to make the cab car work. They did that when 4666 was used for the summer week day trains so they only had to have a 2 person crew - no run around at either end.

Note that it is a NON-standard MU - the 2 extra air lines are main reservoir and the air throttle, not the application/release. When the cab car was being used the braking was only the train line, no independent. Since 4666 has no automatic anything, even the cooling fans have to be manually turned on/off, the electrical part is also NON-standard pin so as to allow the transition to work. This meant that the cab car would only work with 4666 and not a regular locomotive.

As part of the history that I was told - PRR hit the B end in the mid/late 1950s, this resulted in the frame being bent down. All PRR did was to jack it up level and weld across the area where it bent - no steel patch plate, just the rod. Every few years it had to be jack up level and more welding done. There was probably weld over 1 inch think in that section. As part of the work being done the whole B end frame was replaced and that is when the coupler was changed.

The car was running over a short section of the ALLN at Topton today. Will be making a run or two to Kutztown tonight. Prime mover sounds good!

I had the pleasure of riding in the A end cab with Rocky some years ago, and know all about the Waukesha and it's gaskets. And John did a nice job with that coupler; saw it while he was working on it.

Just out of curiosity, what brake stand or schedule was in the cab car? I've developed an interest in cab car conversions over the years, as well as in 'custom' MU applications. With some of the things I've put together, both rail and in industrial automation control systems, I could probably MU a steam locomotive and a tie crane. (That's a joke, Cameron; just kidding-)

EDM,

The cab car had a 26 for the train brake. Rocky had a push-button box for the switches.
They used an electronic bell and a 3-note horn. The reverser was a spare RS-1 reverser, since you could manually control the transition on the RS1 it had the contacts to handle the same for 4666.

I think it may be time to take the herd up to Topton...

I've had some personal experience with 4666 over the years starting with a chance encounter at Princeton Junction when it was the Freehold School Bus and many years later when Julie and I were treated to a cab ride from Ringoes down to Lambertville. I do not recall whether or not there was a trailer at Princeton Junction but I suspect that there was as it one was required on the NY&LB to insure that the signals activated. This is the reason that so many pictures show either a baggage-mail car or a cabin even though there was no RPO service on a particular run an certainly no real need for extra space for a rear end crew.

I often thought that it would have made sense to modify some MP54 trailers to function as control trailers for some of the OEs but the PRR does not seem to have agreed with me. With the differences in control systems between the cars the trailers would have had to have been car-specific and from management's perspective that would probably not have been worthwhile.

I do have a minor disagreement with Brother Moxley - I am very familiar with his work and fully expect to see the circuit diagrams in my e-mail.

GME

PRR4666, thanks for the info on the brake system. I've been involved in a few 26 conversions, and that's just what I would have used. Funny thing about the manual transition; I recently designed and detailed a diesel control box, for eventual use on a small steam locomotive, than realized that one of the potential 'helpers' still had manual transition. So I add another selector switch...

I recognize AML as a brake schedule that was generally used for electric interurban cars. And these were then used for the various "doodlebugs."

The A means automatic brake system; as opposed to straight air used on single unit streetcars. The M means a motor car. The L means it used an L-triple valve. There was also a AMU that used U valves such as U-4 and U-5.