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 Author  Topic: ELCO Exhaust System
Bill Manley

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Post a Reply To This Topic    Reply With Quotes     Edit Message     View Profile of Bill Manley   Send Email To Bill Manley Posted on: May 27, 2010 - 8:54pm
I went back to my warehouse and looked up the ELCO Exhaust system drawings/blueprints that were given to me in the mid 1970's and it said the two main purposes of the butterfly valves are 1) to by-pass the exhaust mufflers for maximum speed and 2) when the butterfly valves are closed the exhaust goes through the mufflers to run with no or limted noise for night time operationss. When run through the mufflers the speed is reduced.

Bill Manley

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BobPic

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Post a Reply To This Topic    Reply With Quotes     Edit Message   Posted on: May 30, 2010 - 7:06am
Bill, I posted a reply but it never appeared here for somr reason. The butterflies on the exhaust stacks channeled the exhause and most of the noise into the sea where it was barely noticible. You could use the mufflers when the engines were idling only, such as out of gear or at very low speed. If you tried to accelerate with the butterflies closed, it would blow them off the pipes. I had that happen twice when we encountered unexpected gunfire and the Skipper said "Get the H out of here". Although the butterflies were easy to replace, the Motor Macs didn't seem to like it when I fouled up. People who climbed aboard from the stern often used the butterflies for hand holds and screwed up their operation. We always checked them before any patrol because they were so important.


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Bill Manley

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Post a Reply To This Topic    Reply With Quotes     Edit Message     View Profile of Bill Manley   Send Email To Bill Manley Posted on: May 30, 2010 - 9:06am
Thanks Bob for the info. I will put a note on the blueprints . These blueprints are an one of the original ELCO Engineering Blueprints that was given to me and it's great to get a first hand explanation of what they actually did. Any and all info gets logged into my archives. Many, Many Thanks

Bill Manley

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Drew Cook

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Post a Reply To This Topic    Reply With Quotes     Edit Message     View Profile of Drew Cook  Posted on: May 31, 2010 - 5:00pm
Fascinating info, BobPic. Thanks!


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Jeff D

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Post a Reply To This Topic    Reply With Quotes     Edit Message     View Profile of Jeff D   Send Email To Jeff D Posted on: Jun 1, 2010 - 4:08am
Thanks Bob. Those butterflies blowing off must have been loud.

Bob, who was responsible for opening them when the throttles were opened? Did the bridge throttle controls link directly to the engines? What were the Motor Macs specific duties when the engines were running? Sorry for all the questions or if they've been answered elsewhere.



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BobPic

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Post a Reply To This Topic    Reply With Quotes     Edit Message   Posted on: Jun 1, 2010 - 5:49am
The butterflies were manually controlled in the engine room. On our boat, the helmsman (me) was supposed to sound a long blast on the engineroom horn to signal to open or cdlose the mufflers. It was easy to forget during emergency actions. The throttles controlled from the bridge the signals for the MotorMac to shift gears just like large ships. Once in forward gear, the throttles controlled the forward speed. Sometimes, the helmsman would signal for forward gear and then immediately shove the throttles forward, racing the engine in neutral. This required the MotorMac to yank back the throttle and get the engine into gear. Neat trick but very dangrerous. MotorMacs were important during fast actions. They were responsible for the gears and watching the temperatures and other meters. Each engine had an overspeed cutout that prevented the engine from running away and they carefully monitored that (even occasionally held their finger on it to prevent cutout in real escape scenarios.). When maneuvering or docking, they had their hands full attending to the bridge signals to shift rapidly. Interesting note: Since you could only operate the speed of the boat with the throttles in the forward position, the speed in reverse was restricted to engine idle speed and power. Several times we needed horsepower in reverse, like trying to back off a sandbar. Altho we were advised that it would damage the gearbox, we had to manually arrange with the MotorMac to ignore our bridge signals and to leave the engines in reverse. Then we could move the throttles into forward acceleration and apply power to the props turning in reverse. At first, we only useed this method in emergency but later did it occasionally just to come roarig to our buoy or doch and slam it into powered reverse to make a spectacular stop. We were pretty good at this altho it raised the skipper's hair a bit.


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Jeff D

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Post a Reply To This Topic    Reply With Quotes     Edit Message     View Profile of Jeff D   Send Email To Jeff D Posted on: Jun 1, 2010 - 6:34am
Thank you very much Bob, great explanation.



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Will Day

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Post a Reply To This Topic    Reply With Quotes     Edit Message     View Profile of Will Day   Send Email To Will Day Posted on: Jun 1, 2010 - 9:49am
Fascinating stuff, Bob. Thanks!

Will

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Frank J Andruss Sr

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Post a Reply To This Topic    Reply With Quotes     Edit Message     View Profile of Frank J Andruss Sr   Send Email To Frank J Andruss Sr Posted on: Jun 1, 2010 - 12:38pm
Thanks Bob, nothing better then getting this information then from a guy who was there.................


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