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What I did this past weekend... [marine]

What I did this past weekend... [marine]

(OP)
Howdy all,

On Saturday I took advantage of the opportunity to "play" on a 134' pleasure [!] vessel of 1960s vintage; had a blast! The owner [who teaches HVAC in a community college] and his family do all the work on it themselves, where possible.

By pre-arrangement the morning was spent bleeding air bubbles out of the hydraulic telemotor system which transmits helm commands from the bridge to the steering flat aft. There was reportedly no manual available for this exact system, but I had managed to find one for something quite similar; we got at least some of the air out, which reportedly considerably improved helm response. I had read quite a bit about telemotor systems but had never had the chance to work on one before...maybe if such work was my trade I might not have had as much fun as I did, but because it isn't...later in the day the owner found out he did in fact have the manuals for both the Hastie electro-hydraulic steering gear and the telemotor system; he stumbled across them while searching for something else [almost all of the vessel's numerous technical materials are still on board]. Doh!

Later in the day I was an acting deckhand / acting assistant marine engineer for a two hour or so transit from one port where she was provisionally tied up to where she would be wintering over. I thus got to see her direct current Diesel-electric propulsion system in action; each of her twin four-cylinder two-stroke-cycle 640 bhp opposed-piston Fairbanks-Morse model 38-1/8 Diesel engines have their speed controlled by a Woodward governor, Type 361691. (I took a picture of the nameplate on one of them, just to ensure I got the model number right). I checked around on Woodward's website, and it seems this numbering convention is no longer used to list their governor products, meaning I wasn't able to find any information on this governor type...do any of you have any info on such a beast in your files, and if so, might you be able to provide me with the model name of its modern analogue? [I've e-mailed Woodward, but have had no response yet...]

Secondly, since I was only a one-day guest I unfortunately I do not have ready access to the propulsion control system manuals, but while aboard I observed that generator excitation is the variable directly adjusted to control the magnitude and direction of propulsion thrust developed by the DC motors [based on the fact there are centre-zero rheostats in the engine room for local propulsion control]. I also noticed the Diesel engine speeds modulating smoothly as the power demanded from them varied...

I have performed Internet searches in an effort to find what sort of indirect input variable this governor or its modern equivalent might use to control engine speed proportionally with power demand but have had no success. I'm speculating wildly that by placing a shunt resistor in the generator terminal connections a proportional current could be made to flow through a solenoid, the core of which could then apply
force to the speeder spring in such a direction as to increase engine speed... Alternatively both a current-activated and a voltage-activated solenoid could work on either end of a balance beam, with the summed movement at the centre of the beam applied to the speeder spring...

Might any of you have a better idea, or know how in fact this is done in similar applications?

CR

"As iron sharpens iron, so one person sharpens another." [Proverbs 27:17, NIV]

RE: What I did this past weekend... [marine]

Sounds like an interesting and challenging day. Fun too!
Was there a separate exciter for the generators and motors?
That would make a big difference in the control scheme.

Bill
--------------------
"Why not the best?"
Jimmy Carter

RE: What I did this past weekend... [marine]

Any photo's, would love to see some of the bits and pieces.

It is a capital mistake to theorise before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts. (Sherlock Holmes - A Scandal in Bohemia.)

RE: What I did this past weekend... [marine]

So was this a steering system with a pair of radial piston pumps put on and off stroke by a stonking great floating lever arrangement? Those look fantastic in a dimly lit tiller flat - especially when everything is made out of phosphor bronze.

A.

RE: What I did this past weekend... [marine]

(OP)
Hi all, back from days off...

Yes, Bill, separate exciters are provided. Did hear back from Woodward, by the way; seems this type of governor is nowadays referred to as Type PG-PL, which uses an air pressure bellows or, on the older models, a diaphragm, to bias the speeder spring pressure and give the necessary increase in engine revolutions as load is applied. [It had occurred to me that my original concept would probably be inherently unstable, but I thought I'd put it out there anyway just in case...] I suspect air bias is provided from the bridge controllers only, since in the rare event the operating engineers had to control propulsion power they would likely have adjusted the governor speed settings and rheostats independently of each other.

If I'm ever invited back, Artisi, it will prove I haven't worn out my welcome, and if you have any suggestions as to which bits and pieces you might find the most interesting I could try to get shots of those.

Sorry Zeus, only one radial piston pump; back-up manual steering is provided from the fantail via a honking big wheel.

One thing the owner is trying to locate is an 1800 rpm 30- or 40-HP DC motor to drive a rotary inverter slash MG set; right now the only source of AC he has is either shore power or a separate Diesel-driven AC generator, and he'd much prefer to run just one DC dynamo at increased load instead of both it and an extra alternator, with neither optimally loaded. I'm suggesting he might be better served to get a static inverter for that duty...

CR

"As iron sharpens iron, so one person sharpens another." [Proverbs 27:17, NIV]

RE: What I did this past weekend... [marine]

Going by basic DC motor theory, if the fields of both the generator and the motor are energized and the armatures are connected in series, then the motor RPM should follow the generator RPM, less armature and conductor losses.
The throttle or speed control need only control the diesel engine speed. The prop speed will follow.
The motor speed does not have to be the same as the generator speed but the speeds should track in close proportion.
Eg: Assuming a generator voltage of 200 Volts at 1800 RPM and a motor rated at 200 Volts and 900 RPM, the PU speed should track closely and you will not need a reduction gear.
That said, I am waiting to hear if there are any other control techniques implemented.

Bill
--------------------
"Why not the best?"
Jimmy Carter

RE: What I did this past weekend... [marine]

(OP)
Hello all,

Had hoped to visit again this past week-end but fell ill, more's the pity, so no pictures, unfortunately.

I did however stumble upon this link

http://stevebriggs.netfirms.com/osmrm/xvillemarie....

about the vessel; unfortunately the links from the thumbnail pictures to those of higher resolution are dead, but the thumbnails are better than nothing.

Additionally, this link

http://maritime.org/doc/fleetsub/diesel/index.htm

is to a manual { NavPers 16161 ] about the two types of main Diesel engines used in American WW2 fleet submarines; although the references in the second half of Chapter 3 [scroll down to the table of contents to find the link to it] are to 9- and 10-cylinder Fairbanks-Morse opposed piston Diesel engines and the ones aboard Still Watch are only [!] 4-cylinder ones, they are all classed as Model 38 1/8 despite the different cylinder count, so virtually all of the design details are identical. The high-pressure air starting method described in Chapter 4 is also what is used to start Still Watch's engines...

My copy of Heat Engines by Faire [ ? - at work right now, so I'm going from memory ] states the F-M O-P Diesel engine was made in sizes from three to ten cylinders, with ratings from 150 to 2,000 HP.

Will keep you posted...

CR

"As iron sharpens iron, so one person sharpens another." [Proverbs 27:17, NIV]

RE: What I did this past weekend... [marine]

I can't seem to find that part number in our system. Can you post a picture of the governor?

RE: What I did this past weekend... [marine]

Tim,

I thought most of the Fairbanks engines used the UG8-PL, however the PG-PL was used on steam turbines and some older medium speed diesel and gas engines, http://www.woodward.com/GovernorsSteamTurbinePGPL....
This page has links to available manuals

MikeL.

RE: What I did this past weekend... [marine]

waross beat me to it, I was going to say what he said about controlling engine speed and therefor motor speed to control thrust.

RE: What I did this past weekend... [marine]

(OP)
New year, same opportunities...

After 1.5 visits, with 1.0 of them happening this past Wednesday, I am pleased to provide an update.

Thanks catserveng for suggesting the govs could be model UG8-PL; I've had a look at its manual, and it seems just as viable a possibility as the PG-PL that the Woodward rep though it might be...

Sorry timhinde, not only did I not have a camera with flash on hand, but the engine room lights were all o/s for some reason I didn't pursue; next time, hopefully, I'll get pictures of the governors.

Base/idle speed of each main engine is 350 rpm, top speed is 720 rpm.

There are three exciter lines [port, starboard, and standby]; each line has a drive motor, a dedicated generator exciter, what looks like a PMG to supply DC to the overall excitation system itself and the propulsion motor fields, and one more machine I'm still figuring out.

Engine room main control panel has two rheostat-looking control wheels, each of which operates a pair of resistors with sliding fingers in a back-to-back Wheatstone bridge configuration which allows the propulsion generator field excitation to be smoothly and steplessly adjusted from full astern through stop to full ahead. I haven't seen inside to ascertain whether there's a Geneva gear or something else to accomplish the next part, but once full excitation is applied to the generator fields further movement of the control wheel toward the ends of its travel adds air bias to the main engine governors to ramp them between base/idle speed and full speed to provide additional output.

Pilot house/wheelhouse/bridge control is effected via some sort of actuator mounted on the back end of said control wheel, with a position feedback system to ensure the settings of the control levers on the bridge are accurately reflected by the control wheels; a control selector switch can be set to provide control either from the engine room or the bridge.

There's also a Mag-Amp circuit in there somewhere, the purpose of which seems to be to preclude inadvertent overloading of the main propulsion generators...more research needed.

Propulsion motor field weakening is provided via a pair of rheostats mounted below the control wheels, but operation of said rheostats from the bridge is not provided since there is insufficient metering on the bridge to allow them to be intelligently adjusted from there. incidentally these are provided to adjust the load applied to the main generators so that full load can be obtained or conversely overloads alleviated; things like hull resistance, towing, etc., can have profound effects on this [ see the volume @ https://catalog.hathitrust.org/Record/001624382 for a rudimentary/elementary explanation of how Diesel-electric marine propulsion systems function; as an operator and not an engineer, I found this very enlightening].

What else...

Oh yeah! Both propulsion motors can be driven from one main generator; to accomplish this the motors are connected in series so the generator can still develop full voltage. The manual states that considerable field weakening must be applied in this scenario to allow the single operating main propulsion generator to be fully loaded.

That's all for now.

CR

"As iron sharpens iron, so one person sharpens another." [Proverbs 27:17, NIV]

RE: What I did this past weekend... [marine]

Thanks for sharing with us CR.
Bill

Bill
--------------------
"Why not the best?"
Jimmy Carter

RE: What I did this past weekend... [marine]

(OP)
catserveng wrote:

Quote:


Tim, I thought most of the Fairbanks engines used the UG8-PL, however the PG-PL was used on steam turbines and some older medium speed diesel and gas engines, http://www.woodward.com/GovernorsSteamTurbinePGPL....
This page has links to available manuals. MikeL.

Page 191 at https://maritime.org/doc/fleetsub/diesel/chap10.ht... says the submarine Fairbanks engines used SI governors...which makes sense to me, since these engines ran at constant speed and would have had no need for air biasing.

Mike, which applications are you aware of where Fairbanks Diesels employed UG8-PL governors? BTW at this point models UG8-PL, PGA and PG-PL all seem to be viable candidates for this duty...

CR

"As iron sharpens iron, so one person sharpens another." [Proverbs 27:17, NIV]

RE: What I did this past weekend... [marine]

a few different applications,

Standby generators at a large Pacific Bell facility

4 large pump units at a flood control district

3 air compressors at a Joint Military base in Australia

Marine propulsion application, diesel electric research vessel

These were all old applications from many years ago, I think in all cases the engines (except PacBell) were military surplus.

Never worked on submarines but I have some old Woodward documents that show a submarine control panel that was used with PG type governors.

Most of the Woodward stuff I have shows the SI governor as a "locomotive" governor.

A lot depends on who was developing the controls and what all the intended modes of operation were.

I also worked on an older fishing processor many years ago that had Fairbanks engines and Heinzmann/Lipps governor and pitch controls, so i think there could e a number of possiblities on what you actually have on the vessel you're dealing with.

MikeL.

RE: What I did this past weekend... [marine]

(OP)
Hello again all, finally got another visit in this past weekend; here’s some more info.

Each of the three exciter lines [port, starboard, and standby] have been confirmed to have four machines, as follows: one DC drive motor, one generator exciter, one propulsion motor exciter, and a four-pole AC generator to supply 60 Hz power to the control circuitry which includes Mag-Amp brand magnetic amplifiers. Incidentally, the Mag-Amp systems I was exposed to when working in generating stations operated at 420 Hz to provide very quick AVR response, presumably not a requirement in this application.

So far I’ve learned that Mag-Amps are used for at least three purposes on board. If I’ve got it straight, the first is to limit the propulsion generator outputs for three conditions, viz., torque limiting, which in reality appears to be propulsion loop current limiting; generator overvoltage; and overcurrent due to regenerative action, viz., when performing rapid or “crash” maneuvering from full ahead to full astern such that if the prop begins to drive the generator it will be limited in its ability to do so, precluding engine over-speed.

The second purpose is to provide propulsion system control from the bridge; turns out the combined control of strength and polarity of generator excitation plus engine governor air bias are all contained within the engine room controller alone, and remote operation of that controller from the bridge is via a pilot motor. Both motive power and closed-loop feedback positioning control for said bridge-to-engine room drive system are provided using dedicated Mag-Amps.

The third is to provide sensing and operating power for the “killer field” control for the main exciters, such that with an engine-generator running but the control selector switches in the OFF position, the presence of generator terminal voltage build-up due to residual magnetism will be detected and bucking field applied until same is reduced to zero.

There might be other ways they’re used that I haven’t found yet...

Tim Hinde and Artisi were asking for equipment pics; here are some of the port engine governor. Sorry for the low quality of the one of the nameplate; the E/R was still pitch-black, and the feeble light of my little LED flashlight doesn’t seem to have provided enough ambient light for our poor little point-and-shoot camera to focus any better than that.



Oh yeah! Just remembered!

If you watch the video re: "Massive Re-development in Port McNicoll" @ http://barrie.ctvnews.ca/massive-redevelopment-in-... you can see a few seconds worth of both the SS Keewatin where I used to volunteer and M/V Still Watch, the vessel where I took the governor pics.

RE: What I did this past weekend... [marine]

Looks like Woodward sold these governors to EMD in November of 1962.

RE: What I did this past weekend... [marine]

(OP)
Thanks much, timhinde...but it does make me wonder who or what EMD is, since Still Watch was built by Russel Brothers Limited / Steelcraft Boatbuilders, Owen Sound Ontario, Canada...might EMD be a sub-contractor to Russel Bros., maybe? I sure don't know...

CR

"As iron sharpens iron, so one person sharpens another." [Proverbs 27:17, NIV]

RE: What I did this past weekend... [marine]

The only 'EMD' that I'm aware of is the 'Electro-Motive Division' of GM, which was renamed 'Electro-Motive Diesel' after GM sold the company to a group of investors back in 2005. They manufactured locomotives, most of which are powered by large diesel engines where a 'governor' would be very useful.

John R. Baker, P.E. (ret)
EX-Product 'Evangelist'
Irvine, CA
Siemens PLM:
UG/NX Museum:

The secret of life is not finding someone to live with
It's finding someone you can't live without

RE: What I did this past weekend... [marine]

EMD not only made locomotives and their engines, but also diesel engines used for marine propulsion, power generation and some industrial applications, they mainly used Woodward governors, actual model depending on application.

It is likely while these governors originally shipped to EMD, at some point they may have been traded in for exchange or upgrade, then sold to your vessel. There are a lot of old Woodward governors and actuators that look similar to yours on the outside, but may have been either originally sold or modified by a governor shop to work as a direct governor (mechanical linkage for speed adjust), a remote speed set governor that could have used air, electric or hydraulic speed set devices, and maybe even just an actuator, driven by an electronic governor.

Maybe your best bet would be to contact your local Woodward shop, I think its Madsen Controls, and see if they can provide any information on our particular governors.

Hope that helps, MikeL

RE: What I did this past weekend... [marine]

(OP)

Quote:

from crshears on 21 Nov 2016: "Did hear back from Woodward, by the way; seems this type of governor is nowadays referred to as Type PG-PL, which uses an air pressure bellows or, on the older models, a diaphragm, to bias the speeder spring pressure and give the necessary increase in engine revolutions as load is applied."

Hmmm . . . so, based on what you're telling me, Mike, the PG-PL / UG8-PL / SI governor designations may have sort-of "evolved" as Woodward developed better and/or different ways of doing the same thing as required by different applications, making the designations somewhat fluid when back-applied to older models.

CR

"As iron sharpens iron, so one person sharpens another." [Proverbs 27:17, NIV]

RE: What I did this past weekend... [marine]

CR,

Well more than once I've pulled governors and sent them to the shop, only to be told that what I sent didn't match the description or part number tag. For the larger governors for slow and medium speed engines there are a lot of physical similarities, the rounded mounting base was a common feature on several of their governors, so long as you got the input speed right to make things work correctly internally, and made sure the output shaft had enough force to move the fuel linkage in the manner desired, and you could adjust the speed reference the way you wanted, you could have a choice of several different governor models that would work fine. There were small differences that may allowed for optimal operation, but for a lot of those engines close was good enough.

But it could also lead to some confusion too, many times I've installed UG or EGB series governors and had problems, only to find sometime in their life they had been modified by some shop, usually for another input speed rating, and they didn't work right.

Overall the worse thing about this is that lots of the governor shops around these days may not have a guy who remembers the "old" stuff, and the push now days for lots of applications it to retrofit to an electronic governor and actuator system.

Sounds like you have quite a project there, remember it supposed to be fun!

MikeL.

RE: What I did this past weekend... [marine]

Even Woodward doesn't remember much of it's governor roots, On January 26, 2011 Woodward Governor Company approved the name change to Woodward, Inc.

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The Help for this program was created in Windows Help format, which depends on a feature that isn't included in this version of Windows.

RE: What I did this past weekend... [marine]

(OP)
Don't worry, Mike; it is still severe fun! The main problem I'm having is finding the time to go aboard as often as I'd like.

Whether it qualifies as a project or not is another question...turns out the owner relocated from Dutchman's Cove Marina back to Port McNicoll without asking for my assistance crewing, which I'm taking to mean our relationship hasn't yet progressed as far as I had thought...

Another fun fact I recently learned was that the starboard propulsion shaft became jammed over the winter, and is at present only capable of 5° or so of rotation either way - and there are no objects wrapped around the propeller, something that would have been easier to deal with than the present prospects. As a consequence SW had to make its transit on one shaft only, with port helm of ~15° having to be applied to hold course. Repair options are being considered, dry dock being avoided if possible due to cost...which is within the realm of reality as the owner is a qualified diver.

One thought is to wrap putty around the joint between the stern tube and the propeller boss, allowing the shaft gland to be completely removed and an endoscopic inspection of the stern tube performed to determine just what the problem is. Once the exact issue is determined, a potential repair possibility is to securely sling the prop to the hoisting eyes on the hull above it, remove the cap, keeper and acorn nut, and pull the prop, then install a watertight "condom" over the end of the stern tube before drawing the propeller shaft inboard. Depending on what's found, repairs from inboard might be possible; if not, it may be necessary, after doing all of the foregoing, to seal the inboard end of the stern tube, remove the "condom" and do the necessary repairs flooded/wet before reversing the procedure to complete the re-assembly.

Might be fun...[big smile]

CR

"As iron sharpens iron, so one person sharpens another." [Proverbs 27:17, NIV]

RE: What I did this past weekend... [marine]

Quote (crshears)

wrap putty around the joint between the stern tube and the propeller boss

Certainly a challenge! I'd be wary of using putty - or anything that creeps under constant loading as a make-do cofferdam. Something that does work is packing all the gaps with neoprene, then putting several turns of Denso tape over the whole lot.

Two fairly obvious cautions:

There's a couple of places where you're a single improvised point of failure away from a major flood, so you'll need to plan for how you'll manage that - potentially on a bit of an ongoing basis.

I don't know how far below the waterline you are, but this sort of job always starts me worrying about how much of my anatomy might get "intruded" if I'm working too close to a hull opening and a seal lets go.

Keep us posted.

A.

RE: What I did this past weekend... [marine]

(OP)
Hey Zeus, all heads are definitely < 10 ft / 3 m, and are probably < 7 ft / 2 m. As to having no n-1 in place at times, good thing it's not my vessel...plus these are just my thoughts; I've had no opportunity to actually converse or even e-mail with the owner for some time, only with his hired hand acting as a go-between. Doesn't make it any less fun, though... smile

CR

"As iron sharpens iron, so one person sharpens another." [Proverbs 27:17, NIV]

RE: What I did this past weekend... [marine]

With the right preparation, that sort of Underwater Engineering solution is pretty attractive. We've done quite a few afloat rudder and stabiliser bearing changes in recent years. The moment when you crane several tons of structure out the water always seems to draw an audience (and it's one of the rare occasions when you'll find the CO watching maintenance happening).

A.

RE: What I did this past weekend... [marine]

(OP)
About that seized shaft...

Met up with the handyman last weekend and inquired if they'd had any luck freeing it up. They had...

Somewhere along they had heard about someone successfully using a lanolin-based product to try loosening rusty parts, so they mixed up lanolin with vegetable oil in some unknown ratio, forced it in to the stern tube, waited a week, and tried rotating it; the shaft turned quite easily and smoothly, with no groaning, grinding or crunching sounds whatever.

Go figure.

CR

"As iron sharpens iron, so one person sharpens another." [Proverbs 27:17, NIV]

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