Please tell me about "Tractive Effort"

[Gary UK]

For years ive seen and known the term tractive effort that a specific lcomotive can exert.

But what does the figure relate to? What does the 200,000 pounds of starting TE of  an SD90MAC relate to?  Is it the force exerted from a start at the draw bar?

I know that its down to 3 main factors, adhesive weight, power, and number of drivers. 

Whats more, how the heck is it measured?

Thanks for any info. 

[UPRR engineer]

Think its like torque, like in a car or truck. I've saw other guys make long post about this and that, pretty much its like that, the weight + HP + type of traction motors +gears = the effort you get at the wheels. As a hoghead, it really doesnt matter.

[J. Edgar]

UPRR is right its like torque .......torque(TE) gets you moving....HP keeps you moving

[samuelpc]

 Al krug has an essay on tractivee effort and HP  on his "krug tales" site

this may answer many of your questions

 

http://www.alkrug.vcn.com/rrfacts/hp_te.htm

[blade]

tractive effort is the pulling force exerted by a locomotive.it is the actual force on the locomotives drawbar or rear coupler.when a bare figure for tractive effort is quoted without a speed qualification this is normally for starting tractive effort i.e at a dead start with the wheels not turning.

[Gary UK]

Think its like torque, like in a car or truck. I've saw other guys make long post about this and that, pretty much its like that, the weight + HP + type of traction motors +gears = the effort you get at the wheels. As a hoghead, it really doesnt matter.

And i get to reply to a UP engineer Thanks bud.

I take it that Hoghead is another name for an engineer? 

Try not to laugh at the back, ive been walking and working on tracks here in the UK for the past 20 years and it gets kinda boring with our small freight trains and glorified street cars. I just wish i lived and worked on the RR over there! 

Anyway, back on topic, thanks for the replys guys, its now abit clearer!

[Gary UK]

 Al krug has an essay on tractivee effort and HP  on his "krug tales" site

this may answer many of your questions

 

http://www.alkrug.vcn.com/rrfacts/hp_te.htm

Thats a helpfull link, thanks! 

[UPRR engineer]

Welcome buddy

Yep thats what we call engineers over here, hogheads.

"Draft Force" is the term used to measure the amount of pull at the drawbar there bud, or the pulling face of the knuckle. The "Effort" is where the wheels meet the rails. Almost the same thing kinda.

Your comment on the SD90's there buddy, ive never saw the tractive effort get up to 200,000lbs on the computer screen anyways. Ive gotten it up to 125,000 once, pulling up a very steep hill leaving a mine. Thought i was gonna pull the train in half. They suck to run, they buck and kick soo hard you think there gonna throw themselves off the track.

 

 

[Gary UK]

Welcome buddy

Yep thats what we call engineers over here, hogheads.

"Draft Force" is the term used to measure the amount of pull at the drawbar there bud, or the pulling face of the knuckle. The "Effort" is where the wheels meet the rails. Almost the same thing kinda.

Your comment on the SD90's there buddy, ive never saw the tractive effort get up to 200,000lbs on the computer screen anyways. Ive gotten it up to 125,000 once, pulling up a very steep hill leaving a mine. Thought i was gonna pull the train in half. They suck to run, they buck and kick soo hard you think there gonna throw themselves off the track.

 

I guess that'l be an over enthusiastic EMD figure (200K). Out of interest, what unit gives the best ride? Thanks for the heads up and info! 

[UPRR engineer]

I like running those SD40-2's... the new GE's are ok IF there taken care of. I've had the worst rides on some of those GE's.