D-tub, a Mobile Hot Tub

Just think... riding in a hot tub past the Transamerica building at night, looking up at the skyline.  Or during the day, waving at the suits scurrying around as you relax to some nice tunes.  The perfect bar crawl mobile, pulling up to a bar in a hot tub, and showering off before going inside.  Or maybe not even getting out at that stop, and just chat away in the tub, drink in hand (alcoholic drinks in RVs are legal!)

Driving down backroads in the eastern Sierras, looking at the stars, or in the empty desert, riding along with nothing but horizon in view as the sun goes down (or, perhaps as it comes up!).

The project is still in the early stages, but here's what it looks like as of 2007-05-10:



It will be an electric vehicle capable of 15-20 mph, with a biodiesel-powered water heater and large on-board shower.  I've made two mobile hot tubs before, but they were both mounted on a trailer and had to be towed along.  Much more fun will be driving from inside the tub, and maybe even road-legally.

This is a very long and labor-intensive project, and I don't want to wait for it to be finished before I start using it.  I've broken up the work into two phases:
Phase I (2007): tub is towed to a location, but is not mobile (except by towing)
Phase II (2008): make it mobile

Phase I:

base vehicle:  1988 Chevy 3500 crew-cab truck with flatbed
tank and supports: a 500 gallon stainless steel tank, and how to support all that weight
shower: large heated shower, with both fresh water and grey water storage
amenities: propane stove (coleman), sink, cooler, speakers, small bar in front of shower, cup holders
heating: biodiesel powered hot water heater
water sanitation: how to keep the water clean and safe
power and electronics: batteries, inverters, controllers, sensors, and motorized valves, oh my!
plumbing: plumbing diagram and features for the plumbing geeks out there
towing: tow bar and tow brakes
shade: for soaks and avoiding the midday sun.
RV: register D-tub as an RV
lighting: fiber optics and LED lighting


Phase II:
overflow management: for steeper hills and fast stops
electric drive system: electric motor, motor not selected yet, but will likely use a 24V, 550A motor controller
safety: an electric vehicle, driving around with passengers immersed in water?  Is that even legal?


Progress
2007-05-29: may have a line on a 100 gallon fresh water tank, trying to secure it
2007-05-27: 4' x 10' stainless steel sheet appears near my work area, quickly traded for at less than salage cost of SS.  This will form the rear seat in the tub.
2007-05-24:bought 60 gallon greywater tank
2007-05-23 received tow brake system in the mail
2007-05-22 received pump accumulator in mail