Edit post

Edit your reply below.

Post Body
Enter your post below.
Duplex in this context referred to a rigid-frame four-cylinder locomotive with divided groups of driving wheels; each pair of cylinders drove its own group. They appeared in the following wheel arrangements: 4-4-4-4, 6-4-4-6 (the PRR S1 referred to), 4-6-4-4 (PRR Q1) and 4-4-6-4 (PRR Q2). The 4-4-4-4s were all PRR T1s except one; the Baltimore and Ohio had one class N-1 4-4-4-4 whose rear cylinders were located beneath the firebox and drove the rear two pairs of driving wheels. The only 4-6-4-4 also had this arrangement. All were "one-offs" except the T1 and Q2. The theory behind it was to reduce the weight of the reciprocating parts of each engine by dividing the power among two sets of driving wheels. Whether the Q2 and T1 were successful or not depends upon whom you ask. The others were not considered successful. BTW - the Pennsy did not use a dash in its class designations; it was S1, not S-1. Old Timer
Tags (Optional)
Tags are keywords that get attached to your post. They are used to categorize your submission and make it easier to search for. To add tags to your post type a tag into the box below and click the "Add Tag" button.
Add Tag