Originally posted by FlankDestroyer
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Destroyers - Fletcher Class
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Generator pictured....
Originally posted by Boilermaker9 View PostThere is a similar unit on for the Ship Service Turbine Generator set. near the aft bulkhead frame 110 As we recall the SSTG has its own condenser independent of the main engine so the ssts can operate by itself with the main engine shut down/secured therefore an auxiliary air ejector unit is required that functions just like the main air ejector.
Attached is a picture of the aft Turbo-Generator for your enjoyment.
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Originally posted by blidgepump View PostI was not aware of the separate condenser for the SSTG. I'll keep my eyes open.
Attached is a picture of the aft Turbo-Generator for your enjoyment.
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Originally posted by blidgepump View PostI was not aware of the separate condenser for the SSTG. I'll keep my eyes open.
Attached is a picture of the aft Turbo-Generator for your enjoyment.
Below is the aux condenser for an SSTG that bilgepump took either on Cassin Young or the Kidd, not sure, it is a snap of one of the SSTG's (Ships Service Turbine Generator). The photo below is of an aux condenser, possibly married to the SSTG above, but again not sure. As all the fletcher SSTG's and Aux condensers were the same it makes no difference. if one looks at the image of the condenser follow to the Condenser Head, (large circular white object on the end of the condenser) one notices a grey rounded lower condenser shell and a straight slightly triangular straight angled inward toward top (left of center in photo). Above the the narrow portion of the flat shell shell is connected an expansion joint (not visible) which intern connects to the exhaust cylinder of the turbine. This is where the steam from the turbine is exhausted into the condenser. it is shaped so the steam expands and contacts the entire area of the condenser tubes for maximum condensation and does not overheat one of the condenser tubes from the condenser the condensate drops down to a hot well and is returned to the feed system eventually to the boilers.
The cooling medium is salt water which flows inside of the tubes, pumped with its own circulating pump which draws a "suction" from a "separate sea chest" and discharges back into the ocean through its separate "overboard discharge." there are 2 large 3or 4 " flange connections on the Head top and bottom the bottom painted Red top painted grey. the bottom is the inlet and the top is the outlet. Now the condenser heads are partitioned, so that was water flows into the head directed down the bottom tubes (I think) and back again through the top tubes overboard through the discharge line (grey). Which can be seen in the diagram below which I believe was printed sometime in the 50's but not sure. One can see by the piping diagram that the aux condenser is a separate unit. I included a list of the symbols as well to help with the understanding. Sorry the Cover page is upside down My bad! Does anyone know if there is a way to remove a photo?
Steam condenses on the outside of the tubes. These tubes are ether 3/4" or 5/8" od "Pipe is measured in ID- inside diameter- and tube is measured in OD - outside diameter) not sure I want to say 5/8" is the correct size. There is a large # of tubes 2 hundred or so, again not to sure been a long time since I retuned one of the things. Each tube is copper nickel and so is the tube sheet not sure of the break down the most common was 90/10 however 70/30 was also used. Only one end of each tube is rolled (Expanded into the tube hole)and belled the other end lightly rolled to hold it in the tube hole and has hard Fiber and Lead Packing and a packing gland nut which goes around he outside o the tube and that is screwed into the tube sheet around the very lightly rolled rolled tube. This is to allow the tubes to expand and contract with the heat and cold thereby while maintaining a pressure tight joint (if a joint is pressure tight it is vacuum tight)
The vacuum in the steam side of the condenser is maintained by the aux air ejectors which have there own condenser.
The salt water circle pump is not visible in the photo nor is the actual overboard discharge. I am not sure if it was mentioned before but the SSTG runs off of superheated steam 634PSI 850 Degree superheat. Note this is why one uses a broom handle to detect invisible steam leaks--ones you can hear but not see--other wise one will have the searching digit removed in one Feld Swoop and cauterized at the same time!Last edited by Boilermaker9; 08 Aug 18,, 19:25.
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Originally posted by blidgepump View PostAnother diagram of the access to the forward fire room.
Fletcher class DD's had access by vertical access.
So up and down was the "Snipes" life.
Also, narrow in the beam, assured easy transition through the opening.
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Originally posted by blidgepump View PostYes, the USS Allen M. Sumner had two (2). While touring the Fletcher's I noted that there was room in the aft compartment for a second, but BuShips for some reason installed just 1. Much to the chagrin of many sailors restricted to "Water Hours".
even the 692 is a crowded engine room. Now this evaporator is identical to ones on Fletchers this happens to be in #2 engine room of a 692 The Units were Grissom Russel 12,000 Gallons per day machines and were pretty much universal in the destroyers.Last edited by Boilermaker9; 09 Aug 18,, 16:35.
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[QUOTE=Boilermaker9;1042634]
In another one of bilgepumps images which by the way are extremely clear and just great images, we have the fuel oil heater described in an earlier post but the long and the short of it is this is a heat exchanger that runs on aux steam. It heats oil to burning temp somewhere around 235 degrees F. The sooner the the FOSH is put on the line and starts heating fuel oil the better it is for everyone. This is true especially lighting off from cold iron.
You will also note there is a fuel oil meter that registers gallons it is that round object in-between the 3 red valve wheels. yep the navy was conscious of all the fuel they burned.
When the temp was hard to maintain it was time to clean it...that was a chore. and a real dirty one at that. no one liked to clean the FOH , or do fire sides, or watersides. A lot of very dirty work
Thought it interesting to see the inside of a Fuel Oil Heater. The drawing came from Boilerman 3+2 1951 edition
it shows the complexity of the heat exchanger and why the boiler room personnel did not care for them especially when they became dirty and doweled! not necessarily easy to clean!Last edited by Boilermaker9; 09 Aug 18,, 22:13.
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Under the protective layer...
One of the challenges faced when touring is identifying the lesser known mechanical devices below decks.
The liberal use of asbestos used to wrap flanges, joints, valves, elbows etc... causes the lay person as myself to attempt connecting the dots ... so I appreciate greatly those who've served and share knowledge.
It helps when I tour ships now and in the future.
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Bilgepump wrote:
The liberal use of asbestos used to wrap flanges, joints, valves, elbows etc... causes the lay person as myself to attempt connecting the dots ... so I appreciate greatly those who've served and share knowledge.
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Originally posted by bbvet View PostBilgepump wrote:
This is also a problem in industry - when I first entered the pharma/bio sciences area of engineering some 18 years ago, the facility drawings we produced "as built" were very difficult because the existing plant drawings could not be verified due to the liberal use of fiberglass and other insulation lagging put in place before the draftsmen could document the actual conditions. This, at least where I work, has been changed and is now a requirement for any and all new work or renovation project. I do remember about 10 years ago working on weekends trying to stay ahead of the insulators in order to produce correct piping drawings for project turnover. And during summer months it got quite hot up in the bldg. mezzanines crawling under, around, and over all the various piping & ductwork. Oh, yea - just like aboard ship!!!!
I am sure bbvet you encountered simular instances during your career that gave you pause as well. I certainly have.
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BM9 Wrote:
I am sure bbvet you encountered similar instances during your career that gave you pause as well. I certainly have.
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Originally posted by bbvet View PostBM9 Wrote:
Well actually, thinking back to the way things were in the 60's, that (asbestos) was just something to be dealt with as a normal part of operations aboard ship. We didn't make an issue of it that I can recall; it was accepted as the way things were and life went on. Certainly not like it has been totally (IMHO) been blown out of proportion in recent history. The photo you've provided does make me think that someone in the staff has failed to do their job in removing/sealing this wad of insulation, esp. in a public area. I wonder how many CASSIN YOUNG or THE SULLIVANS staff members see or read these forum posts.....!
Judging from the lack of light and the missing cover of the florescent lighting ant the one lone light by the ladder my guess is this image was shot in an un opened /restored space. I imagine this is one of the many reasons organizations are hesitant to let people into unrestored/cleaned spaces, least that would be my guess. The damage to the insulation is probably due to being hit or scraped while moving a large/cumbersome object at some period again my guess. Many times I was the cause of such damage, on these ships 692 and 710 especially bringing boiler tubes down into the space and shoving them into the boiler through the access door them into the boiler, those overhead lines on the lower level didn't not look to good when we finished so we repaired them as part of the job. Yes gauges became a casualty now and again! For the tubes in these boilers had three bends mud drum 10"r, belly 31"r and steam drum 10'r. not sure of the degree of bend though, they were on average about about 13-ft long and therefore very unwieldy so yes insulation was not the only casualty! Wow the memories going back to the 60's. removing old ones and installing new ones is a topic for another time.Last edited by Boilermaker9; 14 Aug 18,, 01:21.
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Originally posted by blidgepump View PostOne of the challenges faced when touring is identifying the lesser known mechanical devices below decks.
The liberal use of asbestos used to wrap flanges, joints, valves, elbows etc... causes the lay person as myself to attempt connecting the dots ... so I appreciate greatly those who've served and share knowledge.
It helps when I tour ships now and in the future.
However Main engines were not so much as the turbine casings had to be lifted now and again so we could inspect the "wheels" stationary blading diaphragms, labyrinth seals interstage seals and bearings.although the bearings could be rolled out and inspected without lifting the casing by installing a Bridge to position the rotor and roll out the bearing. When this happened they replaced the asbestos pads/blankets with something else. lastly look close and some of the flanged joints you will see a discoloration brownie in color that is caused by heat burning the paint and some of the insulation...600PSI at 850Degrees Superheat is ......HOT gives some indication what conditions these "snipes" had to work in
Now there is an interesting image bilgepump took is the first one which is I believe the FWD end of HP turbine since these engine sets had a crushing turbine connected to the HP and connection to the crushing turbine. Steam is admitted to the steam chest of the HP and the throttle man spins the throttle and a series of "Poppet Valves" open one at a time to regulate the steam flow to the turbine. the Popet valves are under the springs painted silver. These are similar to the carburetor on a car engine. Inside the non insulated grey cover is a journal thrust bearing bearing and a flexible coupling, in this case the connection from a small reduction gear of the Crusing turbine, which is out of the picture. The LP and reversing turbine are that large white object in the right of the photo. The cursing and hp turbines are separate and are connected the output shaft of the of the causing turbine reduction gear. The HP is connected to the reduction gear with a quill shaft and flexible couplings.
Included are some images to put my simplified description into perspective. Now again the Black and white photo is as built 692 which has the same propulsion plant (propulsion arrangement) as the fletchers. Notice the springs and the gear housing on the as built photo. The other photos I extracted from a naval engineering manual which happen to show the same thing.
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I was on a ship which had a asbestos removed from the main spaces during a Regular Overhaul in the late sixties. There was some snipe bitching afterwards as I recall as IT WAS HOTTER down there. Not sure at this point if we have a better insulator in 2018. The big problem with asbestos is of course airborne particles so if you see disturbed or loose lagging there could be a problem.
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