LPG
The major problem associated with a Rail-Mounted LPG Tank and fuel line is exposure to weather (especially sunlight), and mechanical damage. ABYC Section ‘A-1' requires that cylinders, valves, regulators & safety devices shall be “secured for sea conditions, and protected from weather and against mechanical damage”. The hose (fuel line) is particularly vulnerable to UV and mechanical damage. For this important reason (& more),I would NOTrecommend a rail-mount LPG Bottle.However, I can imagine a multitude of practical circumstances that might dictate a rail-mounted bottle.You’ll probably have to custom build it. A few considerations:1. Build a fixed mount bottom shelf to carry the weight as low as practical.2. Build a quick adjust top clamp to secure the bottle in all axis.3. Try to rout the flexible fuel line (UL-21 LPG gas hose) so it exits the hull/coaming “horizontally” (preferably on the ‘outside’ of the coaming). The aperture must be made non-abrasive and watertight. The hose must be secured, so that is does not “saw” at the aperture.4. Fashion, and use, a cloth (Sunbrella?) Cover for the tank & hose (etc.)HTH,Gord