Re: Photo: Forward Facing Great Northern Rocky (1939)


Dennis Storzek <dennis@...>
 

On Thu, Jun 23, 2022 at 11:10 AM, Jack Mullen wrote:
These *are* grain doors. 20" wide, 7' long. If you zoom in on one of the higher-rez options for this photo you should be able to distinguish two layers of plank in each panel and the darker end grain of the crosspieces on one ply.
I agree with Jack. While the shipper could use any lumber to build a 'grain door', he would have to pay for the lumber. However, grain doors were part of the tariff, to be supplied by the railroad when they furnished the car. To this end the railroads maintained a supply of reusable panels that they collected at the destination, repaired, and returned to the grain shipping areas. These were a standard size (I don't have a drawing handy but the size Jack says sounds correct) typically made of two layers of 1" nominal boards, clinch nailed together, typically with cross pieces on the ends of one layer to better hold the panel together.

Clinch (or clench) nailing was a technique for laminating layers of boards in the days before waterproof glue. A pattern of nails were driven through both layers, the nails long enough to protrude 1/2" or so through the second layer. The points were then turned and driven back into the wood, burying the sharp points and making the nail difficult to pull out. If you google the term you will find numerous videos illustrating the technique, as it is still used in the construction of replica boats.

Dennis Storzek

Join main@RealSTMFC.groups.io to automatically receive all group messages.