Removing the house reveals the lower decks.
From forward, and under the foredeck are two voltage regulators, or speed controls in boxes set athwartships. On the center line, straddling the two regulators, is the radio/receiver. The On/Off power switch sits just above the receiver.
Immediately below, port, and starboard, are two actuators, or servos each adjusting a regulator for power to the two twelve-volt DC motors seen port, and starboard next aft.
On the starboard side can be seen the servo for actuating the rudders. Tucked under the deck on the port side, and not shown, is the rechargable battery - equivalent to four 1.2 volt batteries, for powering the servos, and receiver.
This view shows the aft compartment, on the port side, partially hidden, is the servo for adjusting the rheostat seen on the starboard side. This additional feature was added to reduce the output to the motors further for "crawl" speeds...you can count the propellor revolutions.
Abaft the servo, and rheostat are two bundles of lead ballast ( buck shot ), and then the two rudder tillers.
The power source for the motors is a twelve-volt lead acid lawnmower starter battery which, as seen, sits on a removable "deck" just above the motors. I chose this battery only because I had one...on the lawnmower, and it fit perfectly snug up into the deck housing when placed over it. It gives hours of running time, outlasting the smaller servo/receiver battery which gives out after a few hours of maneuvering...which is plenty.
The last view
gives an explanation of how orders are given to the rudder, and engines.
Housing, and Hull side by side. Notice the most necessary antenna drooped over the hull.
Housing in place on hull, and antenna drooped over the mast...its usual position.
View of the stack, or boat deck. The Foss Company Emblem on the stack says: Foss Tugs Barges Always Ready.
A look at the towing winch from starboard. Notice the box for stowing deck gear.
The transmitter, or Digital Proportional Radio Control System.
Controlling four servos: Left stick - two servos - Rudder - see L ( left ) R ( right ). This stick also works up, and down - controlling "crawl" speeds.
The right stick: two servos - one each - port, and starboard motors. Notice the labeling: starting at the top, and clockwise:
A S = "Ahead Starboard ( motor )"; A T = "Ahead Two ( both motors ); A P = "Ahead Port ( motor )";
T S = "Twist Starboard ( stbd motor back, port motor ahead ); B S "Back Starboard" ( motor )";
The rest is self explanitory. From the stick at the center ( up, and down ) out to the perimeter, is power - stopped to full, and skillfully moving the stick, one can actually steer the vessel using just the engines. The stick is a "joy stick" in the strictest sense, having a circular motion. The circuitry is simple, and can be figured out by trial, and error.
The rudders were modified to be large enough to feel the full propellor wash, allowing almost side ways motion of the tug - "walk sideways".
There is enough power for the engines to actually pull the stern under when up to speed astern, the stern itself taking over as a "dive plane", increasing the "dive". Since the tug is sealed tight, it makes for an exciting manuever...up to a point.
Tug Shelley Foss Dry "Desking"
Author: Carlos Mendoozy