jrs_dodge_diesel

Jim,

We used it as an underway foghorn, so other vessels could hear us. I was also tested everyday at noon (except inport) with the other alarms (fire/general, collision, chelical, flight crash). It was never used for stations or time checks. The only place it would hurt your ears was the bridge wings and the lookout deck above the bridge. And if you were up there someone would always yelled a warning to watch your ears.

There were two ways to blow the whistle. 1 was to activate the automatic fog horn system which operated a big solenoid valve by a timer. The other was for the helmsman to reaach up above his head and pull down on the lever to open the manual valve which was cable operated.

Our engines were a dual plant. We operated 2 main diesel engines and 2 gas turbines (18,000 Shaft HP each). We ran the diesels for low speed work, up to 18 knots. If we need to faster then we kicked up the turbines and shut down the diesel. That would get us to 26+ knots. The diesel was a inline 12 cylinder 24 piston design (vertically opposed), meant more for railroad use. On a ship with limited space they found a good use. They could produce 3600 shaft horsepower each. To start them it would take compressed air. 250 psi. It took the same for the diesel generators. I heard the air start motors before. It sounds like a real big impact wrench with no load on it, then a low rumble as the engine caught.

The turbines were different. They had a hydro start system that used hydraulic fluid to start it. It used a high flow, high pressure (4500 psi) pump that was driven off of the main generator crankshaft.

SoTexRattler

[QUOTE]Originally posted by Jim Lane

**Re: the change of pitch in the air horn is probably because the Co2 is actually freezing up when it leaves the regulator or you were freezing the diaphram on the horn if the line was short.]

Jim, the test I ran way back then was two stage regulation. a HP CO2 gas regulator (non-siphon tank) fixed at 150psi output ran to another adjustable external reg to get it down to 80psi or less so that I could regulate the sound volume of the setup...
No frost or freezup problems as I didn't honk it THAT long! I would've been booted out of the house (or neighborhood) for that much honking!
The pitch change was noticeable each time it was fired off after "airing out" a few minutes.
The harder it was sounded(higher pressure) the briefer the note change to its deeper post-puberty pitch.

Jim, I just wondered if YOUR installation had a note change on sounding.

Keith

Mechanos

Can anyone recommend was size compressor I'd need to operate the pair of 24" Grovers I picked up? I definitely want to use both of them, one adjusted to a slightly different pitch than the other one. Each horn has as 1/8" NPT port on it's inlet. I have a 2 gallon pancake airtank I was planning on using.... if it's big enough.
Thanks....

Also, for those of you using the manual air valve, where do you have it mounted? I'm not going to drill any holes in the roof of my cab. Anyway, the horn will probably be mounted on the front crossmember behind the front facia. I like the idea of using the manual air valve, just can't think of a decent place to mount it.

Also, I noticed that one of them is leaking air pretty badly around the hard plastic seal between the air inlet and the diaphram. Anyone know where to get replacement seals?

Jim Lane

I mounted my manual valve on a bracket and placed it just about above where the post is for the wind vent then I ran the lines backward and down out through the back of the cab.
Jim