Underwater gas burning torch

[Papyone]

Hi, I wonder if this gas burning torch is used in the USA?

 

[Akimbo]

AFAIK, not for decades. We learned about Oxy-Hydrogen gas torches in US Navy Diving schools in the early 1970s but I never actually saw one other than grainy B&W photos in diving manuals.

I am sure that there were several recurrent discoveries of the Oxy-Arc burning process around the world — it is sort of obvious to anyone who learned to stick weld. The earliest recorded use that I have seen was during salvage operations at Pearl Harbor in 1942. They fashioned the torch and electrodes out of steel pipe fittings and electrical tape. See: Descent Into Darkness: Pearl Harbor, 1941: A Navy Diver's Memoir

They still used the giant knife switch on deck in the 1970s (like straight out of a Frankenstein movie) but the torch and electrodes were industrially made.

I have seen attempts to integrate control of a relay into the torch head to eliminate the old "switch on" and "switch off" voice commands but it was too unreliable. The last I have seen, commercial saturation diving systems have switched to using relays controlled from the bell control console but the diver's voice commands remain.

 

[Papyone]

AFAIK, not for decades. We learned about Oxy-Hydrogen gas torches in US Navy Diving schools in the early 1970s but I never actually saw one other than grainy B&W photos in diving manuals.

I am sure that there were several recurrent discoveries of the Oxy-Arc burning process around the world — it is sort of obvious to anyone who learned to stick weld. The earliest recorded use that I have seen was during salvage operations at Pearl Harbor in 1942. They fashioned the torch and electrodes out of steel pipe fittings and electrical tape. See: Descent Into Darkness: Pearl Harbor, 1941: A Navy Diver's Memoir

They still used the giant knife switch on deck in the 1970s (like straight out of a Frankenstein movie) but the torch and electrodes were industrially made.

View attachment 911485

I have seen attempts to integrate control of a relay into the torch head to eliminate the old "switch on" and "switch off" voice commands but it was too unreliable. The last I have seen, commercial saturation diving systems have switched to using relays controlled from the bell control console but the diver's voice commands remain.

I’ve used the Picard P9 underwater gas burning torch during 4 decades. It’s that torch that has served as model to make the PVL that is seen in this video. Actually the PVL is the sole gas burning torch still available on the market.

The PVL is a very good cutting tool, but like every tool it has some Pro and Cons.
The Cons:
Although this torch can be used very easily in the same way as above water if there is some visibility, without visibility it requires more practice because you have to work by ear and with the feeling of the vibrations of the torch.
The torch is more cumbersome than an oxy-arc torch and is therefore not suitable for all cutting work.
The steel must be at least 5 mm thick otherwise it cools too quickly and it is then very difficult to bring the steel to its ignition temperature (+/- 1200 ° C).
It is difficult to cut a back plate in one go if there is a gap of more than 2-3 mm between the two plates.
The steel must be clean otherwise the cutting stops from time to time.
Only oxidizable steel can be cut.
Unlike the electrode, oxy-fuel cutting is very sensitive to the purity of the oxygen and must therefore be at least 99.5%.

The Pros:
If we refer to what the torch manufacturer writes, this cutting method is 7.8 times cheaper than electrodes. When I was still working, I also made such a comparative evaluation and my results were about 4.5 times cheaper.
With a little practice, the cutting speed can be MUCH higher (3.3 times) than any electric cutting tool (except plasma cutting).
Since the temperature of the MAP/O2 cutting flame (2975°C) is lower than that achieved by oxy-arc or ultra-thermal cutting, less hydrogen is produced by the slag.
It generates MUCH less small gas explosions (pops) than electrodes even if there is material behind the structure and is therefore the perfect tool for cutting sheet piles.
Very thick steels can be cut very quickly in a single pass (+/- 15 cm).

For info, for my last cutting job in 2003, my late old buddy Chris nicknamed Papy Two and myself cut this pile Ø 240 cm (7,54 m) x 70 mm thick at a depth of 18 m with low visibility within 13 minutes.