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Senior Crew
Posts: 183
| Subject: Diesel boat question
I don't know why it has taken 50 years for me to wonder about this question about snorkling. The Barbero only had one engine room, FER having been converted to Auxil and storage space, so the question never arose, but could fleet boats snorkle on 3 or 4 main engines? Never thought about it before. I am thinking they could not as I don't know if the snorkle could provide enough air. Also can't imagine what it would be like when the valve closed for a moment. Any one have ideas?
carlb |
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Plankowner
Posts: 9165
Location: Upper lefthand corner of the map. | Subject: RE: Diesel boat question
Engine shut downs at 6 inches of Mercury, High vacuum cutouts. |
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COMSUBBBS
Posts: 6180
Location: Summerville, SC | Subject: RE: Diesel boat question
Under ideal conditions 3 engines could snorkel. 99.9% of the time 2 engines was max was the rule.
When using 3 engines the vac. shutdown was too sensitive. |
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Master and Commander
Posts: 2490
Location: East Coast of Wisconsin | Subject: RE: Diesel boat question
Both Ric and Ralph provide good answers. I can add that I thought the gauge board was a strange place for an altimeter.
Entemedor was a Guppy IIA. No 2 main was gone and in it's place were the previous contents of the pump rooms (hydraulics, AC and reefer plants, etc.) AER got the Hardy-Tynes air compressors in place of the dinky.
We generally snorkeled on 2 mains for battery charge and that in the AER. For single engine operation, usually cruising around, the FER usually got the call. I do not recall ever snorkeling on all 3 mains.
We did have many flame outs following the closure of the head valve. Head valve goes shut when the sea water shorts out the contacts and then the high vacuum cutout tripped the engines. Also had the high exhaust back pressure switch which shut down the mains. It was there to protect the engines if the engine exhaust was not enough to blow or keep the water out of the exhaust system.
Good old days (?).
Ron
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Master and Commander
Posts: 1269
Location: Hopewell Junction NY | Subject: RE: Diesel boat question
Never ran 3 on the snorkel on my SS-407. I did ask one time about that and was told that CFM requirements (550/ea?) for 3 engines would not be sufficient. |
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COMSUBBBS
Posts: 2672
Location: New Jersey | Subject: RE: Diesel boat question
Sirago never snorkled on more then 2 engines because running more then 2 would require more air that could be supplied by the raised mast, forcing what would be many 8" vacuums being pulled. It would be like turning a light switch on and off, on and off...etc.
Bad on the eardrumssssss-what, can't hear you!
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Great Sage of the Sea
Posts: 853
| Subject: RE: Diesel boat question
An old qual question. In calm seas you could snorkel on 3 at max RPM of 600 (F/M), and what good was that no load RPM? |
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Master and Commander
Posts: 2490
Location: East Coast of Wisconsin | Subject: RE: Diesel boat question
"Bad on the eardrumssssss-what, can't hear you!"
Huh?
Edited by Holland Club 2014-07-23 9:11 AM
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Master and Commander
Posts: 1604
| Subject: RE: Diesel boat question
It seemed our shut off failed to work more often than they worked on the Pickerel Guppy III, I got the impression that was fairly standard for smoke boats. If memory is correct Maneuvering had the shut off when all else failed - does that sound right!
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Master and Commander
Posts: 2490
Location: East Coast of Wisconsin | Subject: RE: Diesel boat question
Can only offer an answer for 340 boat. We had a lot of 'flameouts' and I do not recall maneuvering ever having to take the place of the high vacuum switch. Maybe they did manage to get a lick in before the switch but I doubt it. In maneuvering they wouldn't have any idea how long the head valve would be shut if you could recover depth in time, all was forgiven and the head valve would reopen and permit the vacuum to equalize. I would suggest maneuvering wouldn't have tried to guess how long the head valve would remain shut.
Actually, we had enough flameouts without creating more and doing a restart on the mains was a pain especially if we were trying to get in a battery charge.
I do know the altimeter would wind up pretty smartly but by the time anyone could figure you might be exceeding 6" Hg, the switch always got us.
Ron |
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COMSUBBBS
Posts: 6180
Location: Summerville, SC | Subject: RE: Diesel boat question
I'm with Ron on the vac.shut down. In the engine room we could tell immediately when the head valve would shut. The air coming down the induction would stop...DUH.
When that happened the engine room watch would watch the altimeter begin to spin. If the head valve remained shut long enough, just before shut down a fog would suddenly appear in the engine room. When the head valve would open there would be a sudden blast of air and a slug of sea water coming into the engine rooms.
Oh what fun and joy!! Those were the days, my friend, we thought they'd never end........  |
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COMSUBBBS
Posts: 2672
Location: New Jersey | Subject: RE: Diesel boat question
Agree with Ron & Ralph....Our FM's would suck all the air out of the boat until the head valve reopened or the preset amount of vaccume was reached. |
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Master and Commander
Posts: 1604
| Subject: RE: Diesel boat question
I know I've got CRS syndrome, but I thought I only had a slight hint of it. I'm sure you guys are correct about Maneuvering in your boat not having an engine shutoff switch. Honestly, having it in the Engineroom seems more appropriate, but I remember (or thought I remembered) witnessing them hitting it as the boat was well over 6" of vacuum, and on its way to 7". I say the engineroom makes sense to me for it, but I never thought the denizens of the engineroom were as smart as the Electrician Mates. If they were why would they stand snorkel watch in a hot room over the tranquility and relative coolness of Maneuvering.
Luckily my shipmate George can tell I'm wrong, or verify that the Pickerel is the only diesel boat in the entire smokeboat Navy that had an engine cutoff switch in Maneuvering. Unfortunately George is on a well deserved three week vacation, so I'm in an odd predicament - I'm waiting for a lawyer to return from to provide my own redemption. George was an Engineman for short while, and as a stern planesman put many a snorkel underwater long enough to obtain over 6" of vacuum.
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Great Sage of the Sea
Posts: 932
Location: Milford, PA | Subject: RE: Diesel boat question
On both my DBz as an EM, Maneuvering had control of the engines and could shut down if needed. Simply turn the rev control to the left-hand stop and go to batteries. The EN or MM would do the rest. Never did it but it was possible (the EN or MM was quick on the draw).
Snorkel on 2 only for reliability (the Head-Valve cycling on 2 was hard enough on the eardrums). |
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Master and Commander
Posts: 1604
| Subject: RE: Diesel boat question
Thanks Bob! |
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Great Sage of the Sea
Posts: 618
Location: Issaquah WA, USA | Subject: RE: Diesel boat question
As I recall there was a handle in the overhead of maneuvering that would kick out the fuel supply to the engines, causing a engine shutdown. We mainly used it when diving, as I recall. |
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Master and Commander
Posts: 2490
Location: East Coast of Wisconsin | Subject: RE: Diesel boat question
True enough. I did not imply Maneuvering didn't have a cutout for the engines. They certainly did and on most dives (not securing from snorkeling or flameout), they were quick on the draw and killed the engines. EN then just had to push the throttle lever to the lock position and shut the outboard, trip the engineroom and ships ventilation hull flappers and crank the inboard shut. Nothing to it guys, once qualified, always qualified.
I believe what we were talking about was the high vacuum trip. My guess is no one was fast enough to manually do a thing if both engines were running and the head valve shut. Hi vacuum trip killed the engine(s) and it was physically located in the FER. (Actually the AER might have had one too but I wouldn't bet on it.)
When POD was over visiting and we did the Cobia tour, I had the distinct pleasure of twisting the engine control knob in manuevering. It was set so all 4 engine controllers responded when the main knob was tweaked. Hot damn, just like old times!!
Another little EN trick to avoid a restart. When on the surface in rough seas, sometimes the screws would come out partially of the water and the engines would wind up and many times tripped on overspeed. If you were on the ball, hitting the overspeed reset plunger on top of the governor would let the engine get fuel and continue on it's merry way without going through a start up. Did it many times.
Ron |
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Master and Commander
Posts: 2490
Location: East Coast of Wisconsin | Subject: RE: Diesel boat question
You sent your post while I was typing mine.
Right on Pat. There was an air cylinder on the throttle linkage at the engine. When maneuvering hit the lever, air went to the throttles on all engines whether running or not. That is why I said it was only necessary to push the throttle lever down to lock because the air cylinder had already put the linkage in the no fuel position.
Ron |
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Great Sage of the Sea
Posts: 932
Location: Milford, PA | Subject: RE: Diesel boat question
Thinking back, that syncro-servo control from Maneuvering to the engine controls was pretty hot stuff back in the day. Control of 4 engines by a single knob was pretty darn good.
Sure wish I had a C-note for every hour I spent on the sticks. But memories are good enough. |
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Great Sage of the Sea
Posts: 853
| Subject: RE: Diesel boat question
The straight skinny
http://www.maritime.org/doc/fleetsub/diesel/chap10.htm |
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COMSUBBBS
Posts: 6180
Location: Summerville, SC | Subject: RE: Diesel boat question
Thanks "Pete"!! That should answer any and all questions. |
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Great Sage of the Sea
Posts: 539
Location: Palm Bay, Florida | Subject: RE: Diesel boat question
Ralph Luther - 2014-07-29 8:38 AM
Thanks "Pete"!! That should answer any and all questions.
Not so fast Ralph. This older gentleman is a little confused by all the references to inches of mercury. I can remember the altimeter on the diving stand, but don't remember a barometer, except for the one that the Chief of the Watch watched so he could report "pressure in the boat" when we were diving. I think that flameout happened around 38,000 feet + or -, but why weren't the barometers trashed by this large & rapid change in pressure? |
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COMSUBBBS
Posts: 6180
Location: Summerville, SC | Subject: RE: Diesel boat question
Beats the hell outa me, Ken. I guess you'd haveta check with a "weather-guesser" or maybe one of those fair skinned "Quartergaskets".
Seems to me though that altitude and barometric pressure could be two different things.
Maybe one of these educated nukes can enlighten us in 2,000 words or less. 
Which brings to mind something from the DB days on Vacuum. We had a little saying back in the day of working with the Aux Gang..."Everything on this boat sucks except for the drain pump"....a quote from John McMichael who actually made it to MMCM(SS). One hard working dude. 
Edited by Ralph Luther 2014-07-30 6:57 AM
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Master and Commander
Posts: 2490
Location: East Coast of Wisconsin | Subject: RE: Diesel boat question
Ken, you are right on. The setting on the high vacuum cutout was the equivalent of 6000 ft altitude. Whatever that equates to in "Hg is beyond me. A six inch Mercury column would require a lot of sucking to attain. Never met anyone who might qualify for that. Did hear of a person who could suck a golf ball through a garden hose but don't know much about that either.
Ron
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COMSUBBBS
Posts: 6180
Location: Summerville, SC | Subject: RE: Diesel boat question
Ron, I think maybe you are referring to Thelma in Norfolk or "One arm" Peggy in Chasn.. It's unfortunate that Dex has departed on Eternal Patrol and too Adrian Stuke. They were the authorities on that subject. |
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Diesel boat question
