I've been working on a Standard Gauge Crocodile-type electric locomotive for the past while, and I finally have it somewhat presentable. I used an American Flyer 4644 locomotive to start with: the cab looks sufficiently croc-ish, and the curved front of the cab lends itself to the articulation aspect of the thing.
The original Swiss crocs have some very distinctive characteristics. They are essentially a stretched and articulated steeple cab, with the electric motors in the "snouts" and the center section is the crew cab. The motors in the snouts run a jackshaft with an eccentric wheel, which drives the snout's smallish drive wheels by means of siderods, a carry-over from steam technology. All of this is very visible on the side of the crocodile and is quite distinctive.
I decided pretty early on in the project not to try to replicate that drive system. I wanted to use a more rubust motor than I could rig in the small snout compartments or trucks: a Williams dual-can motor unit which is the size of a build-a-loco motor, and takes up the center cab. It wasn't exactly a drop-in to the Flyer frame, but it wasn't too difficult. Each of the can motors drives an axle, which gives all kinds of drive power. So I'm calling it a Tinplate Crocodile, more along the lines of the Dorfan 3930 Standard Gauge Crocodile - although at least mine has the articulated frame, which the Dorfan did not. The Dorfan was called a "Pennsylvania Crocodile", which was a later evolution from the Swiss version, but the whole Croc concept was an interim technology that didn't last long. From what I've read, it seems that it was soon found that the more efficient way to run electric locomotives was with individual motors at the wheels, rather than a bigger motor running those jackshafts... and the articulation also proved to be unnecessary. Interestingly, if you take a later Pennsylvania GG1 and put it next to an older Croc, you can see the resemblance. The GG1 could be seen as an unarticulated - and streamlined - Crocodile!
Anyway, it took me a while to figure out the pivot point for the articulated sections. They started out as a Flyer 4022 flat car cut in half, and then I had to add a piece of flat brass rod to move the pivot point closer to the locomotive's center. The articulated frames swing underneath the frame of the center cab. I show some of this toward the end of the video. I fabricated the hoods for the snouts from 22 gauge sheet metal, matching the curve to the 4644's cab; added lead weights, and redesigned the trim features on the Flyer loco, adding a pair of more substantial pantographs. I also added a Williams reversing board to the dual can motors, which gives such nice smooth, dependable forward-neutral-reverse-neutral cycling. After an early test run, I also replaced the flex trucks of the flat car with Flyer rigid trucks, the flex trucks can be a total pain!
Cow catchers are missing from this one too. I wanted to use the Flyer brackets from the flat car which support the coupler and have steps built in. There really wasn't an obvious way to add a cowcatcher while using that bracket. Anyway, the real Crocodiles didn't have them... maybe a pair of European-style buffers?
Another Standard Gauge what-might-have been, tinplate style!
david
