# Long-distance inspection ROV **URL:** \ **Category:** General Discussion\ **Created:** [September 16, 2020, 3:17pm UTC](https://discuss.bluerobotics.com/t/long-distance-inspection-rov/8170 "2020-09-16T15:17:57Z")\ **Posts on this page:** 1\ **Showing post:** 2
**Author:** ![Tangaroa](https://avatars.discourse-cdn.com/v4/letter/t/ac91a4/32.png) [@Tangaroa](https://discuss.bluerobotics.com/u/Tangaroa)\ **Post date:** [September 16, 2020, 3:36pm UTC](https://discuss.bluerobotics.com/t/long-distance-inspection-rov/8170/2 "2020-09-16T15:36:22Z")
Hi, If you check this link out > [@5.5 hour, 2,400ft pipe inspection with modified BR2](https://discuss.bluerobotics.com/t/5-5-hour-2-400ft-pipe-inspection-with-modified-br2/7276): > > I performed an inspection of a 2,400ft long, 24" diameter treated sewer outfall with a modified BR2. I used two 50cm [3" cast acrylic tubes](https://bluerobotics.com/store/watertight-enclosures/3-series/wte3-asm-r1/) as the chassis to mount the electronics enclosure and thrusters. The two tubes were secured together by attaching the [enclosure clamps](https://bluerobotics.com/store/watertight-enclosures/3-series/enclosure-clamp-3-series/) to each other. I also mounted the thrusters,lights, electronics enclosure and buoyancy to the enclosure clamps. I wanted to have plenty of battery capacity to haul the fiber optic tether, and to have plenty of… The guys at seaview did a long 2.4 km inspection They also have a battery manager which allows the use of multiple battery’s. If you go down the road of topside power. You will have to step the voltage up a lot for that length of tether or use bigger conductors which then leads to a larger tether and more drag. So more thruster Force is needed and so on. Everything you have listed will work over fiber optics with the exception of the USBL which won’t work in a tunnel at that length anyway as there’s too much reflection from the tunnel. I would say you would be better off with a cable counter on your tether so you know exactly how far down the tunnel you are. --- _[View the full topic](https://discuss.bluerobotics.com/t/long-distance-inspection-rov/8170)._