Monday, September 20, 2010

Arming the Monomoy, was 'Super Secret Project'

Yesterday I wrote a bit about our 3 pdr gun and the great surprise we prepared in bringing it out to the End of Summer Bash. But the ten days leading up to the event were a flurry of activity as we worked to complete the naval carriage for the gun and the skids to mount it in the bow of the boat.

The whole business started at a weekly meeting on Wednesday September 8. Examining the incomplete parts of the 3 pdr's naval carriage, the idea came up "what if we put all efforts into getting that gun out to the lake - as a surprise." The oak we'd recieved for the project was improperly seasoned and had begun to check and crack considerably. Even two pieces that were selected for quality and had been fashioned into the cheek pieces of the carriage were severely checked. We would basically have to start from scratch, with no budget and no new materials.

Looking around the Dockyard, we tried to find something with which we could build the carriage. Much of the oak stock was earmarked for the Launch. The plans call for white oak, being better suited than red oak to moisture and conditions at sea in general. Of course, that's when the idea hit to laminate the cheek pieces. Before very long we'd located clear spruce stock, very light but with good tensile strength, and began laminating it together into horizontal lifts with Smith's All Wood Glue. If you've ever worked with that stuff, you know it's tough as nails, bonding even the hardest and oiliest woods, even when burned - the glue will actually bond the wood until it becomes ash. It was formulated by the Navy in the 1950s for use in laminating the cold molded hulls of minesweepers, and we've been using it on the oak keel of the Launch. Thankfully we had extra to spare. The sides were laminated and tested to five times the weight of the gun, using our trusty bottle jack and compression scale - thats 1,500 lbs of pressure on EACH CHEEK. Might not be period correct but dammit it works well. The cheeks were cut, planed, primed and painted a bright cherry red - so that now the laminations are completely invisible.

The axles were cut and turned from several blocks of the original carriage oak that were able to be salvaged. It was our first time turning wood in the shop, but the results were quite satisfactory. The wheels for the carriage were also turned, after being made up of 1" oak planking, laminated and planed to thickness.

The irons holding the carriage together are all stainless steel, chemically blackened and fitted through holes drilled through the laminated cheeks into the oak axles. They are driven in with mallets, then held in place with washers and nuts threaded onto the ends. The nuts are all square, per original drawings, but are also stainless steel chemically blackened.

The cap squares worked well, but need to be improved on. They are not the correct type for our carriage, but they did the job well enough and we ran out of time. Correct cap squares should - and I stress should - be completed and retrofitted within the next month or two.

The boat skids are composed of 3/4" oak planking, jointed and laminated to form L-rails on which the gun's wheels ride. A crude riser was made forward and bolts were passed between the planks of the bow platform - so no new holes were needed. They compress clamps above and below that prevent movement, and provide a good base for the skid risers. For purposes of speed, the risers were made up of short sections of 2x4 stock, needing only to resist the compressive forces presented by the weight of the gun and carriage. For time reference, you should realize that we are up to last Thursday night when these were assembled.

The gun was hoisted into the boat at the dockyard, and situated in a purpose built shipping cradle situated athwartships just aft of the 3-thwart. The carriage was designed to nestle neatly between the 2 and 3 thwarts oriented fore-and-aft. Both were disguised with canvas tarps and covered with equipment bags for further camouflage. The skids were dissassembled after weight testing and stowed under the bow platform with the implements to serve the gun. Six charges were made up from cannon grade powder, each one weighed to 1/3 lb (5.33 oz) and friction primers filled the gap where we hadn't had time to prepare quill primers nor the linstock - and our slow match is somewhere in the US mail system even now.

We wrapped up all preparations by noon on Friday, just in time to depart for the 5 hour drive to the event. The rest, I recorded yesterday.

The whole system performed flawlessly all weekend and all the hard work certainly paid off. Now, we can go back and refine a few items, particularly the skid risers and clamps, in time for operations in October. Special thanks to all involved who helped make this crazy project work, and without a single material or personnel casualty. BZ!


Tomorrow I will discuss the ongoing construction of the Launch and plans for the framing party to come in October.


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