On the afternoon of Friday, February 24, 2017, the C&NW 1385 Task Force received the latest packet of shop drawings for the new boiler from Continental Fabricators for Mid-Continent to markup and approve. The painstaking process was started the following day at SPEC Machine and great progress was made.
Previously, Brett Morley of Performance Engineering had completed a SolidWorks™ 3-D model derived from countless hours measurements of the original boiler by him and others on the 1385 team as well as a study of the Chicago & North Western’s drawings for the locomotive, obtained from Lake States Railway Historical Association. The model provides a 3-D representation to check, among other things, whether and how well all the parts will fit together. Files derived from the model were provided to Continental Fabricators who then created their own preliminary construction drawings that are now being sent back to us to proof, mark up and return. The packet received on February 24th is the latest iteration.
The 1385 team must examine every minutia of the shop drawings to prevent any mistakes. It is a very painstaking and tedious process but the manufacturer will build precisely what is on the paper and it is Mid-Continent’s responsibility to make sure what is there is what we want and need.
A few of the many details being reviewed include:
- Diameters and shapes of each course
- Overall length of the boiler
- Mud ring size, shape, placement, and material
- Shapes and placements of clearance holes
- Size & placement of washout plugs
- Placements of the throttle/superheater header/branch pipes
- Size and placement of the safety valve outlet and appliance manifold outlet
- Placement and size of cutouts in the smokebox
Every dimension on every drawing is going to be checked. Every description of every weld called out will be cross checked. The material listed for each part will be checked. These things will each be cross referenced against the C&NW drawings, actual measurements of the old boiler, and the SolidWorks™ model.
With a project this scope, any mistakes are forbiddingly expensive so the team is proceeding as swiftly as they can without rushing the job. As the first round of checking concluded on Saturday, a fair sized chunk of the job has been completed. So far the Task Force have been quite pleased with what has been supplied from Continental and when finished, all the corrections will be sent back to them. Once those corrections are applied, Continental will send another packet and the process will repeat until there are no more corrections. Despite the intense workload on the Mid-Continent volunteers and partner contractors, the project is staying quite close to the manufacturing timeline and we are getting ever closer to the actual build.