Jeff Livingston
1st Class Member
Brakeman
Posts:14
Send Message
 | | 08/07/2008 10:21 AM |
| It is my understanding that all steam locomotive drivers required counterweights to assist in the conversion of linier motion to rotational motion. Some outside frame locomotives had cast or separately applied weights on the wheel itself, some had independent counterweights fixed to the axles outside the frame and some had a mixture of both. Does anyone know of any engineering reason that one method would be prefered over another or why methods would be mixed? The Oahu Railway's Mikados (similar to the D&RGW K-28s) and the two early Baldwin 2-8-0s (#76 & 98) had counterweights outside the frames fixed to the axles at the main rod connection only. The remaing drivers had counterweights on the spokes. All other outside frame OR&L locomotive counterweights were on the spokes. Just wondering why.
Jeff Livingston
Kaneohe, Hawaii | | | |
|
rkapuaala
1st Class Member
OZ
Foreman
Posts:423
Send Message
| | 08/07/2008 11:23 AM |
| Jeff,
I don't know if this is true or not, but it made since to me. Someone told me, or I read (don't remember which) that the weights acted to counter act some of the stress on the connecting pivot points between the rods and the outside axel. Not sure if I explained it right, but any way, it was sort of like you have the pressure of the rods driving against the connector that was sort of cantelevered off the wheel,,, where is with inside frames all that strees was taken up by the wheel itself.
I figured and probably wrongly so again that the counter weights were reduced on some of the OR&L engines because they were simpled and the connectors weren't subjected to the same amount of force as a compound engine can deliver? | |
I keep forgetting we're not in Kansas! | |
|
Jeff Livingston
1st Class Member
Brakeman
Posts:14
Send Message
| | 08/07/2008 12:50 PM |
| Rick,
Good possibility. Stress would appear to be transferred from an outside/separate counterweight to the axle vice the wheel structure. But why would one method be chosen over another or mixed? The only compound locomotives simpled by the OR&L were #22 & #31 and they had counterweights on the wheels only.
Jeff | | | |
|
armorsmith
Brakeman
Posts:12
Send Message
| | 08/07/2008 1:17 PM |
| Jeff and Rick,
The primary purpose of counterweights are to counter the centrifugal forces (rotational) produced by the WEIGHT of the connecting rod(s) and cylinder rod when the locomotive is in motion. The forces of the cylinder rods getting to the wheels is the function of the PIN the rods are connected to. They are unrelated forces relative to the simple / compound cylinder configuration.
Hope that helps.
Bob | | | |
|
rkapuaala
1st Class Member
OZ
Foreman
Posts:423
Send Message
| | 08/07/2008 1:25 PM |
| Bob,
Thanks, that is what I was trying to say, but couldn't remember exactly how it was phrased, with the exception that I was told (or read) that those same centrifugal forces exerted an unequal amount of stress on one side of the connecting pin and the bearing surfaces. I'm thinking that does not mean the rod connector but the connection to the axel itself.
Also what about Jeff's other question. Why were these weights removed or reduced on some of the other OR&L engines? | |
I keep forgetting we're not in Kansas! | |
|
james brodie
Rosedale East North Yorkshire
Brakeman
Posts:30
Send Message
| | 08/07/2008 2:55 PM |
| Dear Sir, When the coupling rods are fastened to the wheelsets via crankpins then usually the counter balance isn't needed the wheel balance weights counter any inside motion rods, inside cranks for big ends and for sheaves for working the valve system. When the engine has outside frames depending on the top speed the engine will run then the size of the counterbalance weights could be increased and these balances are for the side rods. I have two model 4-4-0 locos with outside frames and balance weights but my 4-2-2 single dosn't seem to need them?
reciprocating was a term we were taught when we were cleaners meaning converting a horizontal back and fore motion to a circular motion
Jim Brodie. | | | |
|
Jeff Livingston
1st Class Member
Brakeman
Posts:14
Send Message
| | 08/07/2008 3:24 PM |
| Bob, James,
Thanks for the replies. (James, please do not call me Sir. That was a different life). I'm aware of why the counterweights were needed, either wheel mounted or external, but wondering why specifically on outside framed 3 foot narrow gauge locomotives on the OR&L some would be all wheel weights and some mixed external and wheel. There seems to be a common factor in the mixed counterweight locomotives that the single external counterweight is on the axle with the main rod connection and those wheels with only side rod connection have wheel weights. I can see where it might be desirable to get as much weight outside the frame for stability but that doesn't seem to be the reason. At least on the OR&L.
Jeff Livingsotn
Kaneohe, Hawaii | | | |
|
james brodie
Rosedale East North Yorkshire
Brakeman
Posts:30
Send Message
| | 08/14/2008 4:08 PM |
| To Jeff, yes Sir I won't forget Sir.
I just noticed your address.! Where were you some eleven years ago when I had ten days holiday at Wiakiki Beach?
regards the mix of balance weights I would need to see a photo as maybe some of these choo choo's had three cylinders?or axle driven feed water pumps.
Me mam said if I couldn't touch me forelock then I had to say Sir and if I didn't do as me mam said she would clag me
Yours ever so humble one of the serfs from the middle of the North Yorkshire Moors.
I jest a bit of humour makes the world go round.
Jim Brodie....potential platform edge white line painter ! | | | |
|
Jeff Livingston
1st Class Member
Brakeman
Posts:14
Send Message
| | 08/14/2008 5:39 PM |
| James,
Eleven years ago and more I was right here in Kaneohe. Why didn't you call? As soon as Shad gets the new picture posting thing going I hope I can get pictures up again. Since the last change I have failed consistantly. Take a look at a K-28 and you'll see that the first, second and fourth axles have counter-weighted wheels and the third axle has an external counterweight. With the exception of some appliance differences and oil rather than coal fuel, the OR&L had four of the same locomotive. The first two Baldwin Consolidations owned by the OR&L dating from 1878 had the same set-up. All the other OR&L locomotives had all counterweighted wheels only. No three cylinder locos except the two Shay's and no axle driven feed water pumps. Since I'm just an old retired Navy guy and not knighted, sir is unnecessary, and how come you didn't drop by during all that time I was in Holy Loch?
Jeff Livingston
Kaneohe, Hawaii | | | |
|
james brodie
Rosedale East North Yorkshire
Brakeman
Posts:30
Send Message
| | 08/19/2008 2:52 AM |
| Mr Jeff (Sir) I didn't get to Holy Loch 'cos my working area was from North of the Thames to Edinburgh and from the East and North East coast to about the middle of the country and although I didn't need a passeport to go to Scotland if I took any of their work I might have had a haggis hoyed at me.
I have a cousin who lives in CA he was on Flat tops during his Navy service. I've only ever been skipper on Princess 32 or 38 motor cruisers and that on the Calledonian Canal from Inverness to Banavie.
On our railways our K classes only went up to 5 so unless I know how to open a photo from somewhere I don't know what a K-28 looks like.
More later as Modom is calling..........Jim. | | | |
|
tacfoley
1st Class Member
Foreman
Posts:368
Send Message
| | 08/19/2008 3:38 AM |
| Dear Mr Jeff - Mr Brodie and I come from an era when we were taught that if you had not been personally introduced, then good manners dictated that you call people 'Sir' or 'Mr' when communicating at long distance- as indeed, we are doing so here on this site.
Although not a Yorkshire lass, my mother, too, would, and indeed did, have fetched me a good clag round the ear for forgetting my manners.
You will notice that on MY posts, I do the same as the redoubtable Mr Brodie. 
I was called 'Sir' for almost twenty years of my military service, and I don't miss it one bit.
tac [formerly Sir, and now nobody at all] | | | |
|
Jeff Livingston
1st Class Member
Brakeman
Posts:14
Send Message
| | 08/19/2008 8:46 PM |
| My Dear Tac,
Lest you misunderstand, I too was raised in a home where manners mattered and still do. As to being properly introduced, I believe that those of us who frequest these forums do so without the need of formal introduction as we are drawn together by a common interest where age, rank or seniority have no bearing. My aversion to being addressed as "Sir" is based on that belief as I am no better a being than the next. I too was addressed as "Sir" for seventeen of my twenty-seven years of active duty haveing come "up through the ranks" and don't miss it any either. If the tongue-in-cheek exchange regarding the use of the word "sir" lead you to believe that this Colonial did not comprehend the requirements of dignified correspondence I apologise for causing the misunderstanding. Perhaps I would have been better served by responding "Don't call me Sir, I work for a living".
Jeff Livingston
Kaneohe, Hawaii | | | |
|
james brodie
Rosedale East North Yorkshire
Brakeman
Posts:30
Send Message
| | 08/20/2008 2:44 AM |
| | Dear Gentlemen My tongue in cheek replies are an escape for me used to gentle leg pulling at work sometimes to relax a situation as when I would climb into a loco cab and the driver would be thinking why is he here ? More later Modom needs me....Jim | | | |
|
rkapuaala
1st Class Member
OZ
Foreman
Posts:423
Send Message
| | 08/20/2008 10:35 AM |
| Sir Brodie,
Where was you when I was in Edinborough in 1975 trying to get work on the NA pipeline?  | |
I keep forgetting we're not in Kansas! | |
|