Exploring an Early Colonial Mine

Its been a while since I posted. Recently we sent the Trident into a newly discovered flooded pit in an early colonial mine. The mine is said to good quite deep underground, but until recently only minor adits were uncovered. After recently clearing what was thought to be a dead end, a partly filled and flooded pit was found on the other side. To one side we could see it opened up to a passage. Feeling this might be the lost pit to the deeper part of the mine, we sent in the ROV, and we weren’t disappointed. We’re already planning out our next visit with the ROV to go even deeper and see what we can uncover.

Here are some clips from the 45 minutes of video we got.

Hopefully soon we will have a much more crafted video of what we’ve uncovered during this expedition.



Amazing, nice footage! Please keep up posted with more videos. Out of curiosity, how did you manage the tether cable? It appears to be a complex structure with many protruding elements where the cable could get entangled.


@Jose Thanks! I cannot deny that the tether and several other reason were a concern of mine for getting stuck. Thank goodness the tether is somewhat buoyant, and stayed near the ceiling of the passages, and away from all the debris that littered the floor.

When we explored a pit and down to some lower passages though, the risk factor went up. We did get stuck for a few minutes, but with one person working the controls and the other gently pulling on the tether, we got it free.

When the final video for our first run is ready, I’ll post it here. More visits to this mine to come in the near future too.


I can imagine all the stress operating in such environment. What was the longest track? We have operated the ROV in some fairly complex artificial structures, and I must admit that the fear of entanglement was too high, so we played safe by staying close to the home station (30~40m). After that, we started to explore the idea of developing a navigation-assisting system to improve reliability and safety. I’ll let you know if something comes up, maybe it can help people exploring complex environment.


@jose We didn’t go too far on the first visit. I think we did a total of 45-50m for this first run. 30m of it was following the first drift. We then came to a pit that dropped 6-9m, did a 180 degree turn and began following another drift for another 10m or so. Nothing too complex for the first run. We had taken our time to look for side passages or mining artifacts.

When we reach the furthest point in the lower drift, the walls and floor began to vanish and we were in total darkness. We think we might have found a very large stope the records of the mine spoke of. That was when we somehow got stuck. Once free we decided to get a few more images of a few things and then called it a day. We’re working on a plan to return to the possible stope with better lighting.

I’d be interested in learning about your navigation system. we don’t have a planned return date yet, but hopefully it won’t be too long from now.

I’d also be interested in knowing more about where you have explored with your ROV. I saw you ROV on the page for the university website you have a link for in your profile.

Best Regards,

Here is the 22 minute mini documentary of our expedition to find the lost shaft in this colonial mine. There is a lot of interesting footage, especially when digging out the passage. The Trident footage comes in at around 12:00.

We should be returning in November for a second run with the Trident. I hope to have additional lighting. We’ve also been experimenting with 3D modeling the underwater passages and have had some positive results. We hope to improve our results with better footage from the second visit.

1 Like

I’ve recently become involved in a project that is going to be sending an ROV into freshwater springs and underwater caves and I was curious as to your set up. You appear to be doing stuff very similar to what we intend to do and I have a few questions. Are you using the standard Trident with 100m tether? You mentioned adding additional lights to the Trident; has that affected how it moves through the water? In another of your threads, you mentioned that snagging was a concern. Thank you in advance for your time and my team and I have got about a million more questions.

1 Like

@ben.gulmon Yes, I’m using a standard Trident with the 100 meter tether. I also use the JXD controller along with a video headset for my copilot. Since I’m so focused on piloting the Trident, I find it better to have a second set of eyes focused on examining the surroundings of the Trident.

I have not added the additional lighting yet. I’m building it right now. I have had a GoPro on the Trident before and did not experience any issues with how it moves though. My design for the added lights does account for drag it might cause, and should minimize it.

Yes, I think for any ROV pilot navigating caves/mines, getting your tether snagged or wrapped onto something is a concern. ALso in a mine I worry about causing structures to collapse and trap the Trident. I was just watching from the UNEXMIN project recently and though they are a million dollar project with seasoned professionals, I saw they too were worried about that as they navigated a flooded cave.

The best advice I can give is to proceed slowly and try to remember the things you had to weave around on your way in. When returning follow you entering path, use your tether as a guide. I often locate my tether first before heading back. In an emergency though, you can try pulling it back by the tether. It can take a lot of stress. When I’ve had to do that, I have someone else slowly pull it back while I pilot the Trident to keep it from the roof of the cave/mine or any of the sides.

If you have any other question please let me know. Also, I’m a caver and member of the NSS and local Grottos, so I’m very interest in you project. I’d love to hear more about it.

I look forward to hearing from you again!

1 Like

We’re down in Florida(based at University of Miami, but all the springs are at least an hour north of us). We want to sample for microplastics in the sediment and grab water samples from inside the caves/caverns in the springs. It is still fairly early stages so we’re open to ideas.

Do you not like the onboard camera on the Trident? I haven’t upgraded my Hero3 but I guess the newer ones have better video than 1080@30fps.

@ben.gulmon Wow, that sounds much useful than what we do. Sounds like a fantastic project to be a part of. I’ve seen some people create devices for the Trident that is triggered to draw a sample when it bumps something. Ingenious way to avoid having to create a complex circuit to do the same. Its all mechanical with a spring to power the action.

I’m happy with the video from the ROV. We’ve used it in the little documentaries we create and I’ve never been dissatisfied with the footage we have gotten. On occasion I attach a GoPro facing down so we get more footage from a different perspective.

My old OpenROV 2.8 had 720p for the video, and I was not completely happy with that. Now that I have the Trident, I’m thinking of redesigning the old ROV for challenges that the Trident can’t handle.

Keep me posted on your project and feel free to drop me a question any time.

Do you have a link to that bump triggered arm? Depending on how it functions, that could be exactly what we are looking for I haven’t been able to get my hands on a Trident to see what it can actually do, so I would like to pick your brains on what its actual limitations are.

That was a long while ago, so I don’t have the link handy. I’ll see if I can dig it up though.

Well, I’m not sure what kind of limitations you’re speaking of. We can chat about in via email or Teams.