OK Sean - we need to check on diameter and pitch of historic narrow boats - i.e what happened when FMC changed from steam to Bolinder - what did they do with propellers ???
Maybe Neil knows - I know he is lurking (:-)) -- Malcolm >From the change in stern design, I suspect they used smaller propellers, matched to the Bolinder. Though a large, slow-running propeller is much more efficient than a small high-revving one for propelling a slow-moving boat, it's a problem in a shallow, crud-infested canal environment. Sean
