The Steamboating Forum

I sense a misunderstanding here (I may well be wrong).

The confusion is between crank lead and cylinder lead.

Regardless of forward or reverse, the steam will always enter the HP first, as the LP is supplied from the HP exhaust (normally, but not let's get into that), so the LP never leads. Direction is only achieved by which END of the cylinder is fed first, not which cylinder. The change is done in the valve chest, so effectively there will be no noticable difference in power in either direction.

There is still a power pulse every 90degs whichever way it is turning.

wsmcycle wrote:I understand the start-up will be accomplished. I am probing an understanding of running power when the HP is leading the LP versus the HP following the LP. Is there a best running direction for this 90 deg crank. Leading? or following?

Got you, sorry for the misunderstanding.

Mike Rometer wrote:I sense a misunderstanding here (I may well be wrong).

The confusion is between crank lead and cylinder lead.

Regardless of forward or reverse, the steam will always enter the HP first, as the LP is supplied from the HP exhaust (normally, but not let's get into that), so the LP never leads. Direction is only achieved by which END of the cylinder is fed first, not which cylinder. The change is done in the valve chest, so effectively there will be no noticable difference in power in either direction.

There is still a power pulse every 90degs whichever way it is turning.

Ditto

Meanwhile I still haven't learned whether the right crank on a stern wheeler leads the left crank when in forward motion as with locomotive practice. Just curious. Makes no difference.

Mike