Blind drivers on C-19

[mudhen]

Why did the D&RGW C-19's  and smaller engines have blind drivers. The total driver centre to centre distance looks smaller to me than on the K-27's,28's 36's and/or 37's.
The only thought that comes to mind is spure lines must have been much tighter, making it necessary for blind drivers to negotiate track curves and switches ?
Weight wouldn't have been a factor, I don't think.
Bachmann made the Spectrum Series Correct. And a fine job they did of it too.

[Kevin Strong]

You are correct; the drivers are blind so the locomotive could navigate tighter curves without the need for the builders to put in a lot of lateral play in the drivers. It was very common on narrow gauge locos, and also on some standard gauge locos as well. Why they didn't do that with the Ks, I don't know. My guess is that they figured out a way to engineer more lateral (side-to-side) play on the drivers so that they could keep the flanges. It would be interesting to talk to the mechanics who keep these locos running to see if there's any noticeable difference in flange wear from driver to driver.

The tread of the blind drivers were typically wider than the flanged drivers, so they would be less prone to falling off the railhead. For instance, the blind drivers on the EBT's mikados are 6.5" wide, where the flanged drivers are 5.5" wide (including the flange). On the PRR's standard gauge locos that had blind drivers, it was 8" and 6". It's rare that you see this modeled on a locomotive. Bachmann's C-19 is one of only two large scale locos I've seen where this is the case.

Later,

K

[mudhen]

Kevin.
Thanks for your input, but I think you did this on purpose.
C-19 is one, what's that other ?, you left me hanging.

[Chuck N]

My guess is that by the time the Ks came along all of the mainlines had been upgraded.  They weren't used of spurs very often, if at all, usually because of weight restrictions on bridges.  I think that I read somewhere, that the Ks could not run west of Gunnison, because that stretch could't handle them.

Chuck

[grcaprez]

Blind drivers were part of the technology of the time. By having flanges only on the front and rear wheel sets the middle wheels were fixed in the frames. The drawback is that all guiding forces were put on the leading flange which, consequently, wore fast and ate the rails. Better metallurgy after 1900 allowed for side play in some axles along with side play of the coupling rods on the driving pins of these axles. One type of 2-8-0 loco I know on my road has the first and third axle fixed, thus resulting in a shorter fixed wheel base than if the first and fourth axle were fixed. The guiding force in curves is thus divided among several outward flanges.

In short: blind drivers belong to the 19th century and were superseded by side play in some axles and better steel for crank pins and side rods.

Gion

[Barry BBT]

In a discussion with Lee Riley, he said the blind driver width on the Tweetsie locos was 7 inches.

Never forgot that.

Barry