NYC 0-8-0 switch engines

I recently purchased a copy of "New York Central Steam" written by David R. Sweetland. When talking about NYC 0-8-0 steam switch engines, he more than once uses the term "eight-coupled" switchers. Can anyone tell me what that term means?

Thank You......

DET760,

Refers to the number of driving wheels on a steam locomotive, but the term is misleading.

"8-coupled" means 8 drivers, but they are actually connected by the rods into two groups of 4, one on each side of the locomotive. You may also see references "6-" or "10-coupled".

Hope this helps.

The RODS only connect the four wheels on each side, but the wheels are fixed to the axles. (Very few rail vehicles have wheels that are free to rotate at different speeds on the two sides: TALGO trains, I think, have wheels that are not fixed to the axles, so the wheels at the two ends of an axle are free to rotate relative to each other. And some modern low-floor trams of European design have wheels on "stub" axles: by not having an axle running across from one wheel to the other, it is possible to make the floor lower, and hence boarding from street level easier for elderly riders.)
So all eight wheels on a 080 rotate together.

shlustig, Allen Hazen,

Thank you both for you answers.....

I have a 1920 engineman's hand book
that has both systems,Whyte's and
whatever you want call it.
Whyte's system made the wheel arrangement simple .An example of
the other ,0-8-0 was called an 8 wheeler.
A 4 coupled could be a 2-4-0,2-4-4,
2-4-6,4-4-4,4-4-6.The old system
used wheel,coupled,name(mogul).
I am glad they changed. mel

mel,

Thanks for your reply. You're right about Whyte's system being less confusing......