14m ladder is “required” for DT.
Other options if at least one caver is on SRT.
Use the split pitch at the side of DT as detailed by Steve above.
Alternatively: Attach a 10m rope to the ladder and put through a pulley jammer. When the caver reaches the top of the ladder let them have a “rest” sitting on the lifeline whilst you pull the ladder up to the top.
They can then continue their ascent.
I have done both these options in the past.