PC8 3 man submarine

(Click on photo)
 

The PC8 is a scratch-built model of a 3 man sub! This model is fully operational and is based on a design that was 'homebuilt' by two nautical engineers in Corpach ,near Fort William way back in 1972, it was developed to hunt for Nessie. The full size version was not very successful - my model seem to have overcome most of the full size's problems. It is very very manoeuvrable, use the flexible tank system and pump water in & onboard to ballast the model when diving- it's a static dive model not a dynamic diver i.e. It can dive straight down while stationary just like the prototype.

The submersible is my latest model offering ! - its scratch built and it was my first go at a underwater model, I did not want a military type sub model, and some of the mouldings of a military type sub are hundreds of quid, without any internals....a costly dream....  The lake where we sail can become murky several times of the year, so I wanted a bright coloured model, so I could see the model underwater at depth, I did a bit of research on the net and came up with some images on some early 'diver lock out type submersibles', and an interesting web site giving ideas on how to build a full size submarines at home, one of the examples was the 3 man submersible produced in the early 70's by 2 engineers who were looking for the loch ness monster!

The body of the sub was actually constructed from steel sections of a oil drilling platform Leg. This was also believed to withstand the pressure of deep dives...they then went on to apply one of the first domed Perspex observation windows to the front of the craft...this was pioneering stuff in 1972 ! Once they got the craft on the water the problems started, if proved to be very difficult to control , and steering was less than precise ! The large observation window did allow  an excellent operator a view of the loch bed, but the drive system did tend to stir up the debris and so vision was often
cloudy and subsequently reduced ! The lights that are on the front of the vessel were also more of a hindrance , they cast a yellow light on everything and they were found to be temperamental and very thirsty on the power packs aboard the sub. The sub was 'laid to rest in late 1974' and a subsequent sub was built....


The model is 30 inches long, and 9 inches in diameter, powered by a single 540 drive motor spinning 4 bladed 40 mm prop. The body is spun fibreglass tubing ( and this tubing is also used in the water treatment industry for things such as swimming pool filters) its cheap to buy and fittings such as flanges can easily be added to sections of tubing. The internals of the model can be removed on the tray that unbolts and can be slid out through the opening in the rear. So access to the RC gear is easy. The rear section contains the drive motor the waterproof pushrod glands and the RC gear, the middle section contains the pressure switches and the dive failsafe unit, the front section contains the ballast pump and the ballast tank, actually a Speedo armband!

The model sails on the surface approx 75 % submerged, to dive the model pumps water inboard, the pumped water is fed into the arm band, the additional weight of this water makes the model sink, the armband swells with the water and compresses the air trapped inside the hull.......to surface all you do is run the pump in the opposite direction, the water is expelled and the model regains its original weight and floats, the swollen armband returns to its normal size and the air is no longer compressed. By altering the amounts of water on board you can adjust the depth of the model. The model has enlarged dive planes at the rear and an enlarged rudder, as my model like its full size counter part was a nightmare to steer, the new bigger planes make the model a pleasure to sail.

The model is powered by 9.6volt nicads from D cells from emergency lighting ! its controlled by 4 channel Futaba system, ESC is a M Soniks sub module. Run time is about 2 hrs between charges. The model features 8 white LED's for lighting - great at night in a murky pool !

All in all a model sub for under 250 - and that's radio, ESC the lot !