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Pete Nolan
January 6th, 2006, 09:15 PM
I'm about to install decoders in a bunch of articulated steamers: LL 2-8-8-2s, Bachmann 2-6-6-2, Rowa 2-8-8-2, Micro-Ace 0-6-6-0, and maybe even my Big-Boys, although I may sell the last.

I'm presuming, due to rail slippage, there was no way to truly synchronize the front and rear engines on the prototype. Is that a wrong presumption? Or were the cylinders synchronized?

If synchronized, was there a pattern? Were the front and back engines "quartered?"

I ask because, when I look at four LL mallets, there doesn't seem to be any rhyme or reason to how the engines are synchronized, and it would be a simple matter to adjust one engine. The snychronization would hold because the gearing dictates driver position.

Any thoughts?

N&W
January 6th, 2006, 09:23 PM
Look at piccies of real ones - that should give you some idea ... ;)

http://spec.lib.vt.edu/imagebase/norfolksouthern/full/ns968.jpeg
http://spec.lib.vt.edu/imagebase

[ January 06, 2006, 04:30 PM: Message edited by: N&W ]

John Moore
January 6th, 2006, 10:00 PM
Its rare to find any running footage of articulateds running with the front and rear engines matched as far as driver position. And on compounds definetely not as the high presure cylinders got the steam first and would be in motion before the low pressure cylinders recieved their steam.

SuperSteam
January 6th, 2006, 10:01 PM
The engines were never synched and would not stay that way if they were because of slippage. The only reason i can think of to want them synched is to minimize vibration. But that would be hard.

Besides, dont you want to listen to the stack talk as the engines go in and out of synch?

If you really have BigBoys to sell, let me know!

Dave

Powersteamguy1790
January 6th, 2006, 10:02 PM
Pete:

The N scale models aren't in sync. I would refrain from trying to get them in sync.


Stay cool and run steam.... graemlins/cool.gif :cool: :cool:

NP/GNBill
January 6th, 2006, 10:04 PM
I concur, I was watching a DVD on Big-Boys the other night, and the rear drivers were slipping while the front ones had traction. I don't think I've ever seen footage of one with both engines in sync with other. Sooner or later I would imagine each set of drivers would slip causing them to get out of sync with each other, or back in sync for that matter. This is an interesting topic, I've never thought about them being in some form of sync with each other.

Pete Nolan
January 6th, 2006, 10:39 PM
OK, so my presumption on the prototype was correct.

Now, on our N-scale models, especially the LL 2-8-8-2 with it's one geared axle, could it make a difference in tractive effort if the engines were in synch? I expect the answer is not really. I'll take a look on the layout after the decoder installations. There is a difference in tractive effort between individula models. Could the good pullers be synched differently from the weak pullers?

Just wondering . . .

Chris333
January 6th, 2006, 11:45 PM
http://forums.railfan.net/Images/Chessie/WM_0-6-6-0.jpg
http://www.ironhorse129.com/Prototype/Mallet/Baldwin65/GN_Mallett.jpg

David Leonard
January 6th, 2006, 11:58 PM
It wouldn't make any difference to synch the LL mallet's front and rear engines, but it might make it more interesting to watch. Some modelers have done this just for looks.

Powersteamguy1790
January 7th, 2006, 01:05 AM
Originally posted by Pete Nolan:
OK, so my presumption on the prototype was correct.

Now, on our N-scale models, especially the LL 2-8-8-2 with it's one geared axle, could it make a difference in tractive effort if the engines were in synch? I expect the answer is not really. I'll take a look on the layout after the decoder installations. There is a difference in tractive effort between individula models. Could the good pullers be synched differently from the weak pullers?

Just wondering . . . Pete:

The majority of LL 2-8-8-2 are very poor pulling loco's. I have four and two are surprisingly good pulling loco's (20-22 cars) while the other two can barely pull 12-13 cars. They all appeared to synched in the same manner.

I can't explain why some can pull so well and the majority are really poor. LongTrain and I spent many hours on the phone discussing the reasons for this disparity in performance.


It all comes down to the one geared driver per set of drivers.

The original design called for two geared drivers and LL used one geared driver for the majority of the 2-8-8-2's.

Maybe LL actually slipped in two geared drivers /set of drivers in some of their loco's? That's a possibility.That could be the reason for the improved pulling power of some of the 2-8-8-2's.

Stay cool and run steam...... graemlins/cool.gif :cool: :cool: