An Extinct 80 Foot Shark

If you say "K4s" to a railfan, especially an older one, they will invariably think Pennsylvania Railroad. The K4s Pacific (4-6-2) is as much a symbol of the Pennsy as the keystone itself. If by some remote chance the topic turned from steam to diesel you might ask "Is there a diesel that shouts Pennsylvania". The railfan might pause a bit, but I'd bet the next words from their mouth would be "Passsenger shark" or "BP20"...

PRR Class BP20 "Shark"

A BP20 is to the PRR as a DD35 or a Veranda Turbine is to the Union Pacific. Nobody else had one. They were a unique design with a unique look and a nose shared by the T1 duplex steamer and Baldwins DR-4-4-15/RF16 freight diesels. Over 80' long coupler to coupler they were about ten feet or so shorter than another Baldwin giant, the BP-60 "centipede". Like the centipede they were meant for fast passenger service. There weren't many of each, by Pennsy standards, but back in the late 1940's they were part of the parade around Horseshoe Curve. They should be on the diesel roster of the Allegheny Eastern.

The BP20 is specific to the Pennsylvania and I don't think it has never been mass produced in any scale other than O. Most of the models I have seen are brass. There are a few kitbashes here and there and a resin replica in 1:160 . Apparently created by splicing RF16 models together it was not to scale and very unpopular with Pennsy modelers...

Ken-Ray Shark Shell

I can't afford brass models, especially at EBay prices. I haven't been fortunate enough to find a body shell on the same site. Even if I did, it was made to fit a PA mechanism, which is much too short. My only path to obtaining a BP20 model is to create one myself. I took a shot at it and so far I'm pretty happy with the results...

BP20 vs DL109

I based it on the Life-Like model of the Alco DL109, another odd diesel design. While the DL109 is not as long as a the passenger shark it's close, give or take a foot or so. The real shark has a wheelbase just over 46' - 3" bolster to bolster. The DL109 model scales about 43'. It's not correct, but it is long. Long enough for me.

I have to confess that I followed earlier modelers footsteps by cutting up V-Line and ER body shells. I took a bit more care in that I made the shell 80 scale feet long. The other cause for complaint was using the freight sharks cab and nose. The ER and the V-Line models have the short nose of the RF16. The BP20 had a rather drawn out profile. To replicate this I used bits and pieces of the shells I had to stretch out the freight nose...

Bits and Pieces

I used the DL109 mechanism with only a minor modification. The shark has recessed cab doors. I ground away just enough of the frame to clear these. I used a rotary cutting blade rather than an actual grindstone. It works much faster...

Modified Chassis

Once I modified the frame the shell fit snugly enough to stay put right where it should...

Snug Fit

None of the details on either shell match the real locomotive so I cut them off with a chisel blade. I then filled in any gouges or gaps in the body with putty. I did a preliminary sanding and then brushed on some "brunswick green". The paint helps bring out any faults in the finish. I can eliminate these with a second sanding (I hope)..

Preliminary Paint

Here's the passenger shark in progress compared to its freight counterpart...

PRR BP20 vs BF16

None of my drawings show a specific dimension for that long nose so I "guesstimated". It's definitely longer. I may have gone overboard. Still it looks pretty good to me. Hopefully it will look better when I get the sanding done. Once I get it right I'll have to make another A unit and a B unit. Back in the 1940's The Pennsy management required 6000 HP for every passenger train. That meant that, except for the two unit centipede, all of the passenger diesels were three unit sets. At the time each set was considered one locomotive. This led to those odd classifications for these sets like BP3, AP3, EP3 and FP3.  Unfortunately, these classifications won't work as soon as you buy the latest from EMD. An E7 set and an E8 set would both have the same classification. By that time, however, the management had realized that diesels (except those Baldwins) can be mixed and matched on an individual basis and classed each unit accordingly.

So far I've accumulated 6000 HP sets of other diesels assigned to passenger service. The Baldwin products are the only one's missing. At least they were till now...

Baldwin, EMD, Alco and Fairbanks-Morse

Regards,

Frank Musick

Shop Foreman

Allegheny Eastern Railroad