My fire dept. has always used cutoff saws for vertical ventilation.
Due to the way the roofs are constructed in the city (70% are galvanized roofing sheets, the rest varies between asphalt shingles and old ceramic tiles) and the fact that all roofs are peaked (with different angles, but most of them between 30° and 45°)... in my firehouse we decided to go for a ventilation chainsaw to do the job (the tempest ventmaster chain saw).
The specifications of the chain saw, and the chain itself (the raptor carbide tip) said that we were able to cut all of these materials, with little to no damage to the blade or the chain.
We tested the saw and trained in simulated roofs and it worked perfect. The only two times we used the chainsaw in real fires (we're an engine company, so we don't get to work on the roofs that often), were on warehouse fires (walls of galvanized sheets)... and both times the chain got a lot of damage (broken and bent teeth), and the last time even the blade of the saw got a bit damaged.
We've got to the conclusion that the cause of this damage, was that during some of the cuts the firefighter using the chain saw encountered some steel beams. Even tho' he avoided the beams, he still had to cut the galvanized sheets that passed over the beams.
We decided to not use the chain saw ever again on warehouse fires, except there's a rescue involved (firefighter or people trapped inside).
My question is: is it normal for this to happend? I thought that this chains were harder, but it looks like we're gonna need to change them every couple fires... and the blade got some damage too!!!
Any experiences with chainsaws? It would help a lot to get some feedback about this ventilation chain saws.
PS: Sorry if my english sucks, i'm not from the US. Thank you!
I am confident that this is not a chain or blade issue. Anytime you hit a steel beam with a chain or even a wheel that has carbide tips on the cutting surface you are going to cause some damage to the cutting surface.
Thanks for the reply Frank,
We were thinking the same about facing a steel beam with the chainsaw (even just a small touch) and damaging the chain. How is this saw going to react in an average private dwelling fire? is it going to still get some broken teeth but in a smaller number?
We have both a chainsaw and a cutoff saw. We have had the same problem with corigated steel roofing and grain bins. Dont care what the company reps. tell you, you will damage the blade on the chainsaw. The chainsaw works great on asphat or tarred roofs and does a real good job breaching wooden walls but for the price difference of a new chain over a cutoff saw blade we always use the cutoff saw on steel roofing and siding.
On a private dwelling roof or a normal commercial roof the Vent Master saw you have is great! check out the ventilation DVD from FIre Engineering Tactical Perspective Series. We use that very saw under real fire conditions.