[A/S] Re: Two questions

["nickcrowhurst" <NickandSandra@xxxxxxxxxxx>]

I like to tow our Excella 25 with a full water tank for the lower 
centre of gravity, especially having seen the results of Airstreams 
rolling over. The desirability of this, as discussed on the list, 
will vary from trailer to trailer, and from owner to owner, but one 
thing I would not do for any distance is to travel with a part-full 
water tank. The problem is called Surface Water Effect, and it is 
what sinks roll-on ferries, and causes great care in the design of 
tanks in ships. Put simply, the water surges to the outside of the 
turn when the trailer goes round a bend. In a ship, the water surges 
to the down-hill side, just where it's not wanted, and the ship is 
more prone to capsize. In a trailer, several hundred pounds of water 
slopping around when making a turn is going to impair stability. 
Anyone who doubts the awesome power of the Surface Water effect 
should take a big tin tray, perhaps 2 feet across, put an inch of 
water in the bottom of it, and try to walk across the room. I fill my 
tank till the water pours out of the filler, or I empty the tank 
completely. The worst case would probably be a half full tank, where 
250 pounds of water could slop from side to side. If the tank is 
full, obviously the centre of gravity of the water can't move, 
relative to the tank. On a similar principle, last year, home in 
England, I was driving towards a bend when a meat truck came round 
the bend towards me. Inside the truck were dozens of cattle carcases, 
hanging freely from hooks off bars in the inside roof of the truck. 
As the vehicle turned to the right, the carcases swung to the left, 
and two tons of swinging meat rolled the truck over onto its side. He 
missed us, fortunately.  From Nick Crowhurst.