The CT13 Uhaul
camper does not have surge brakes
, actually no brakes
at all. The larger VT16 does have surge brakes
. I believe that single tube tongue is just Uhaul's standard design as it is used on most of their cargo trailers. I have not had any towing issues with our Uhaul camper, or when I rented their cargo trailers.
EDIT: the larger Uhaul rental trailers that have surge brakes have a "V" type tongue with a straight extension for the brake mechanism. The non-brake trailers have the single tube tongue.