How on earth?!...

[Willy2]

How did the big boy make it around large curves? In the few videos I have seen, the locomotive is going fast around some big curves. Not really sharp curves, but still, well, curves. It's such a big locomotive I would think that it wouldn't be able to manage those curves.

Willy

[eolafan]

Answers: (a) sometimes it didn't make it if the curves, especially in yards, were too tight, (b) that's why you never saw one too far East where the curves are much tighter than in the wide open west.

[louisnash]

It was articulated.

Check out www.steamlocomotive.com/articulated/

Brian (KY)

[edblysard]

The Big Boy, and the Challanger, are both articulated locomotives, with hinged leading engines.
The front engine, or leading set of steam cylinders, pivots or swivels on a plate, seperate from the boiler.
The rear set is fixed in place.
Which is why, when a articulated locomotive goes through a sharp enough curve, the front seems to still be going straight for a while, before it turns.
Both locomotives were restriced from certain yards and routes because of this overhang.
The length of the Big Boy accuents the overhang quite a great deal, the locomotive can be half way through a curve before the nose begins to turn.
Note on both Big Boy and Challanger, the flexiable steem pipes between the front cylinders and the rears cylinders.

Ed

Articulated steam locomotives are not all that rare, but you would need a steam nut to give you a list of them all.

[Anonymous]

QUOTE: Originally posted by edblysard

The front engine, or leading set of steam cylinders, pivots or swivels on a plate, seperate from the boiler.
The rear set is fixed in place.

If I recall correctly, a few of the Articulated had both sets on swivels to compensate for the overhang and to allow passage through tighter curves. Of course these would have been the smaller Articulates, the bigger boys needed power more than manuverability.

Jay

[Modelcar]

....Add to the hinge feature the driving wheel sets probably had some of the wheels without flanges to accommodate the curves such as in yards and turning through a switch to access another parallel track.

[Willy2]

Wow, that's cool how the front set of steam cylinders swivels on the curves so late. I have seen the Challenger in action and I noticed a little bit of a swivel, but not much. In the big boy videos I could see the swivel easily but didn't know that it helped the engine around curves. I did notice how the engine appeared to be going straight until the last minute, but thought nothing of it.

Willy