Quartering?

[The Dude With The Hair]

 Then why did the PRR Turbine need to be quartered?

[tdmidget]

 WRONG! If the force is exerted as a torsional force throught gears, chains, etc then quartering is not necessary. Quartering is needed on an engine with rods connecting the piston to the wheel. If the cylinder was on TDC or BDC then the rod is trying to push in a straight line and no torque is produced. If the force is torsional to begin with then it does not matter.

[The Dude With The Hair]

 If I recall, with the PRR turbine the turbine was geared to one pair of driving wheels and the power was transferred to the others by the side rods....so if it was dead centered, again, there'd be no way to exert rotational force on the other driving wheels to get the locomotive moving...at least I would think.

[timz]

 Next question: did the PRR turbine 6-8-6 need to be quartered? Did siderod electrics need to be quartered? And siderod diesels?

(Answer is yes, but lots of people will say no.)

[miniwyo]

 Ah! That makes perfect sense!

[The Dude With The Hair]

I assume you mean why the rods are a quarter turn apart from each other at a stop. The reason for that is otherwise it would be possible for the locomotive to stop with rods at dead center, in which case the locomotive would be unable to start again under its own power. The cylinders wouldn't be able to exert any rotational force on the wheels.

[miniwyo]

NOT the third amendment...  Why are steam locomotives drive rods in quarter?