Scope: Inspect 1800 feet of 60 inch inner diameter pipe (interior pipe inspection) with the BlueROV2. There will be a maximum of 1.5 knots (2.6f/s) current of clear water inside the 60 inch pipe and the ROV will be traveling against this effluent. The longest span will be 920ft. For the final leg, the pipe steps down to 48 inches for 200ft where the current rises to 2kts.
Thrust: If we opt for the 30 degree thruster configuration, will it provide enough power to pull the
7.5mm tether 920ft through the pipe with a 1.5kt head current?
Theoretical: 920ft Fathom 7.5mm weight in air: 26lbs. 30 degree forward bollard pull: 24lbs.
Unknown: Tether Friction through water being neutrally buoyant.
Power: What kind of run time am I looking at with this set-up? 2.5hrs? Will be using 4 Lumen Lights.
Tether: Is the maximum length for the Slim Tether 200m? For this project I could really use the Slim
with it’s lower drag coefficient (assumed) if it is available in 300m. Would a 1000ft roll of CMX Cat5e
or Riser cable work solely for this job with the Binder 770 connectors? (I would be purchasing the
BlueROV2 but would not need the 300m tether for every situation and would purchase a 150m
tether with reel to get started). Main Question would be if the BlueROV2 would be able to pull the
Fathom 7.5 920ft against the current.
Control: I assume that under full power, the controls will be a bit touchy! I hope to mitigate this with
the 30 degree thruster mounts as I would not need so much the strafing actions. Just forward
through the pipe while recording video is about all the maneuvering I will be doing.
I have used the 12mm neutral VideoRay tether and it is quite bulky. I have 125m of the ~4mm Deep Trekker tether which is nice all around. Seems the Fathom 7.5mm would be a great in-between.
I’m enjoying the forums so far, thanks to everyone out there.