10/30/2026
6933 Update. The lever lock has been installed and the latch has been made. From the 1850s through the turn of the century the standard method of weighting a diver was the use of chest and back weights, known as horseshoe weights. The back weight had ropes that fed over the divers shoulders with fittings that attached the ropes to the studs on the breastplate. The ropes ran through hooks on either side of the bonnet to hold the helmet down. The ropes also helped keep the bonnet from turning, and if the bonnet came loose from the breastplate the weights hooked to it kept it from floating away.
In the late 1800s more divers began using weight belts. The safety advantage horseshoe weights offered in bonnet protection dissappeared. The solution was to add a locking mechanism to the helmet. The first one we know of was the pivoting lever lock. A hinged lever on the bonnet rotated down into a lock stop. Simple. Perhaps too simple. The lever could come out of the lockstop easily if the pivot was loose or it got snagged. Adding a ball on the end of the lever to bring gravity to the party was tried. It helped but not enough. Over the years we began to see helmets from the early 1900s coming into the shop with a homemade latch made from sheet brass. The breastplate lockstop was drill for a pivot pin and a cotter pin to hold it closed. Again simple but with a problem. You better have spare cotter pins because on this evolution there was no tether on the lock pin so they could go bye bye very easily. The US Navy took the idea the final steps for the Mark V. They made the latch itself stronger and changed the lockstop so the lock pin could be chained to it. Later commercial helmets adopted spring loaded drop pin type locks.
For the second gen AJMS commercial helmets we would have liked to stay with the simple lever lock but for a diveable helmet securing the lever is essential for safety. We decided to mimic the shade tree latch design of the 1920s. We just have to keep a good supply of machined cotter pins on hand.
The other milestone this week is the transceiver mounts are in and the transceiver has been test fitted. This helmet is the second helmet we have done with the low side comm cup. The speaker mounting bracket takes it design cues from the WWII Buie Helmet. It being so close to the diver's cheek having the assembly as close to the bonnet shell as possible is important. This mount tucks the speaker into the cup about as far as it can go. The last bit of soldering to be done is the nametag. That's a job for next week. Remember, when you dive standard gear keep your ankles below your ears. Dive safe.
