shipboard engineer

You have a serious problem that no amount of books will help you with, experienece and hands on are the only way..

The person(s) you need are most unlikely to be found on CR4, they will be sitting in Old People's Homes around the coast!!

I suggest that you contact various homes and see if you can find a few still active shipboard electricians.

With regard to motors etc., you will find shops that can rewind and re-insulate even better than new, but not cheap......

The only other way would be to convert the ship to say 220/115volt AC (normal US voltage), which might be cheaper in the end. Equipment could be picked up much, much cheaper, the 2nd hand market alone (ebay) would be just great for you.....AND younger people understand it much, much better!

A further method might be to keep what still works with DC and add an AC system for those areas where equipment cannot be repaired/replaced easily.....this makes you really flexible when bits go wrong......double up on emergency stuff like bilge and firefighting pumps from both systems.

I worked on RN Aircraft carriers in the 60s and 70s and they were still mostly 220volts DC Ring Main Sytem (built in the 40s & 50s!), which is a really nice system, but a modern AC system is still better, Insulation is better and in a seagoing system, that is very important.

ok,that's got me thinking differently.thanks for your help.

You are looking at the problem from the wrong angle.

You are quoting manufacturers names not types of equipment or systems. The type of equipment you will be looking at will be faceplate starters, heavy duty relays, DP battery switches, sensing relays, etc.

There was some great DC technology around in the fifties which consisted of basic items, but still can't be matched by today's technology

What you need is web site or books with old DC motors controls, in order to identify the type of equipment - not the manufacturer.

Now to answer the question - as far as I know the Star electric motor company is long gone, but Cole Hersee is still going and they have a current website (note double e)

http://www.colehersee.com/sitemap/index.htm

http://www.jamestowndistributors.com/userportal/search.do?freeText=cole%20hersee&page=GRID&history&AdWords&engine=adwords!6456&keyword=%28cole+herse%29&match_type=

Check out these links, I don't know where you are, but there are pages of distributors on the web

thanks for your input.Here's some examples: the one piece that really baffles me is the G.E. magnetic contactor,cat.#11K2201, CR-5230-B26, 7.5HP, 115V.DC, 60A., Navy Spec.17C17, 50DEG. C., D.O.M.-June 12, 1943.Made @ G.E. Schenectady,N.Y..side note..- (My mom said she worked there in 1943 and said she prob. worked on that piece but for some reason can't remember).this controls a motor generator which I know little about.It has: alt. #5A8275A37, formCG21618 ,440V., 10.5A., PF.9, 3PH., 1800RPM, 7.2KW, 8KVA, no.I82I833, 40deg.C, drip proof, D.O.M.1941, SEP.EXC.115V.,cont.... now,on the motor end, which is close coupled,is: G.E. DC motor model 94A398, type CD, Frame75, shuntwound 115V., 87.6A, 11.5HP, 1800RPM, no.182I842, drip proof, cont.. 40C., D.O.M.1941, CG21617.any ideas?

Firstly, where are you located? This will help if there are any old ship's electricians around your area, it will make it worth their while!

I would also suggest a web page, which might get hits for equipment and people.

Also, do not forget ebay and similar......

Best of luck.

I'm in Tampa FL.

I did some Engineering work on "Blue Guitar" a 1967 Motor Yacht that had the same electrical system.

Quite frankly, 115 VDC is scary as hell. It can kill you in a heartbeat.

I tried to talk them into converting to AC but to no avail.

Here are a couple of links for more information on Blue Guitar and her crew, perhaps you could find the old Ships Engineer through these links.

The Vessel was built by Camper & Nicholsons, GBR in 1967

http://www.charterbrochure.com/exumac/crewprofile.html

http://yachtspotter.com/ysp2_ycard.php?foo=20091029

A GOOGLE Search for AC/DC Motors will turn a lot of sites including books on design and application.

I would convert to AC.

A healthy respect for any voltage is good, even 12 volts from car batteries can wound severely due to the possible amps, but to be "running scared" of 115 volts DC, is unhealthy and does not contribute in a positive manner.

I worked on 220 volt DC systems on RN Aircraft carriers, where each generator could produce up to around 22,000 amps........and we had 8 of them if I remember correctly! They could all be online together, feeding the ring main...........

I remember only one accident that was at all serious, when an Artificer apprentice placed his screwdriver across the main bus bars of a running generator (accidently), while earth chasing, and then tried to remove it with his bare hands! He was partially blind for 3 days and lost all the skin off his hands, but a few weeks later he was as good as new.......I personally know of no deaths on 220 VDC, although I expect there were a few from before I joined up.........

All RN ships built up to about the middle 50s were 220 volt DC, then the NATO electrical supply version was brought in at 440 volts, 3 Phase, no neutral.....now that really is a killer.....! We lost a lot of people at first in the late 50s, and every year a few more.....mostly due to stupidity.....

I personally cannot believe that 115 volt DC is as dangerous as you make out...... provided of course you do not have a pacemaker and that both feet are not immersed in sea water........arc burns to hands & eyes are the biggest worry......

I am curious if you have 12 years experience as a marine engineer was not DC motors and generators part of your training?

DC starters are fairly straight forward manual or solonid actuated resistance starters.Overload dash pots trip the no volt release mechanism to stop the motors.

Small HP motors would be shunt field type, Larger a combination of shunt and series fields possibly with interpoles.

I am sure there is some info on the net and or tech college librarys. I do not think coverting your systems to AC would be very economical unless your moters and generators were suffering from old age insulation break down.

Brushes and commutators should be kept in good condition

Good hunting

Dear Garth,

if I was the person on site (on Tug?), I am sure that what I learnt all those years ago would come back to me very quickly, but the person who asked the original question is unexperienced in DC.....

Furthermore, modern motor insulation is vastly better than it was in the 50s, when the Tug was built......

I personally believe that a dual system would probably be the best way, provided that there is some space for the necessary extra generator, or I would personally recommend changing it all out.......for more modern AC equipment, probably good secondhand would be fine.....

Safety is the first priority with sea going craft, there can be no half measures......

Some how I think the ships electrician will have precious little to say about replacing DC with AC on an old tug. Too vocal about not knowing DC and they will replace him before they replace the motors. The Tug is probably at its end of life too.

DC is still alive and well, even with the push to VFD controls. DC is simple and straight forward. The theory is easily understood, and there are many books on DC control. Motors are available brand new, and rewind shops can handle the larger sizes.

For a small fee GE will usually provide the documentation on their motors, especially if you have the serial numbers. Ge is still actively rewinding DC machines.

The original question was lack of knowledge, not how to replace it wholesale.

GE may still have the manuals on record for the control items.

Look around for some old military manuals and or copies. We used DC motors and controls for main propulsion and I remember classes on them at MM/A school in North Chicago in the 60's. If you can locate someone with the old books from the electricians classes there, you might be able to get the info you are looking for. If not try MSOE in Milwaukee. Also some of the older sub guy's will have intimate knowledge of the old DC systems and controllers. We are still using some DC motors and controllers now on 10 to 250 HP units here in Cincinnati. What is the problem you are experiencing?

Our maintenance engineer tells me most elevators (non hydraulic) are powered by DC motors. Perhap Otis or some other elevator company have some literature which could bring you up to speed on basic DC motor operation. Just a thought in case you can't find any retired submarine electricians.

I have a 1940's electrical hand book with all this stuff in, that I collected when I worked on these old things in the '70's. It'll cost you £10 and you'll have to pay the postage & packing. Not for sale on ebay!

See if you can find a book called Electric Motor Repair by Robert Rosenberg. When I was in the navy this was a common book in the motor repair shop; basically used for repairing and rewinding motors, and it has a lot of info on motor control, both AC and DC. When I bought mine back in the 70s it cost 15 bucks. Is now a lot more expensive but maybe you'll luck out. Check your local library. Orange County FL does not show it but maybe Tampa will have it.

BTW, in Nam I was an brown water Navy electrician on a converted LST that had 3-wire 250 VDC for all hotel loads and pumps. Three phase 440/117 distribution system was used for lighting, receptacle, and electronics.

I just got home from 4 10hr.days working on the tug last nite, and read your comments.i thank all of you for your input,and will spend the wk.end researching.I've been doing this and other similar type work for almost 35 yrs.It's nice to be able to share this challenge with you guys and get inspired to keep going.I'll have more questions on DC 115V gensets,as we have 2 on board,and will be servicing these soon.

skipper, i am in Tampa, FL and may be able to help you. let me know if i can be of assistance. i have relationships with industrial and marine electrical contractors that do considerable work in the area. let me know if you are interested.

Good Luck!