trailer tongue length?

[fastlap]

I am having a nrc motorcoach built and I wish to pull a tag trailer with it , Does anyone know what tongue length is required to give clearance in the worst case scenario like pulling out of a gas station and turning 90 degrees trough a dip or swale ? trailer and truck will be 13'4" tall thanks ..T

 

[Weramongo]

I think mine is 6' and haven't had a problem yet.

 

[KAYE RIVERCITY]

.....nose of trailer to back of truck 6'-4"....not far enough-need more tongue length.....should be able to turn 90 degrees to right and left without any interferance.....if I use roll-off wrecker with the stinger I can extend it and do a 90 ....if I use the Volvo I can't do it....need a stinger for the Volvo[not made]......wanted a House trailer lift[ 6 way] but the company went out of business.....$6400 installed.....too bad/so sad....maybe after I get moved to the other house I'll just build one.....geofkaye