equivalent human power

1 hp = 746W, 2 blokes = 250W (ish).

Stab in the dark to get things moving!

a man is friction limited to pushing about his own weight on a flat surface. If he can dig in his feet he can push 2-3 times his weight.

What you need to do is see how fast you want to move this train. A cat could do it on a flat with steel wheels, but slowly. Going faster also needs brakes.

So a 5000 pound device to go 1 foot in one second is 5000foot-pounds/second - about 9 HP and it will accelarate at 1 foot/sec/sec. in 30 seconds = 30 feet/sec.

.9 hp = 3 feet/sex and so on. You can use the large motor, start it and let it glide, and a smaller one for more time and better control and less space and cost. A motor will also need to be geared down to match the speeds.

Friction is critical here.

Quote So a 5000 pound device to go 1 foot in one second is 5000foot-pounds/second - about 9 HP and it will accelarate at 1 foot/sec/sec. in 30 seconds = 30 feet/sec.

Now try it for half an hour!

I was taught that the horsepower unit was actually calculated to match the power of 2 horses- ensuring no motor would be outdone by a horse. I believe it takes approx 3 people to hold a horse back, thus:

1 horse = 3 men = 0.5 HP = 373 watts

divide by 3 men

373watts/ 3 men = 124.33... watts/man

I agree with John: 2 men = 250watts (ish)

It depends on how long the people are working like this. My recollection is that short-term power capability greatly exceeds long-term - my recollection is hazy, but it could be factor of at least four. Railways are renowned for low effective friction, so much of their peak effort is probably expended in acceleration. But what happens when it is windy?

The best motivator will be the agreed 250 watts to sustain the duplicated effort of two men. Add to this about 3 times that force for acceleration which would have been the short term maximum human effort. I would go with 1000 watts and a CVT to apply the force to the rail.

I think I read somewhere that a man in VERY GOOD (Lance Armstrong) physical condition could produce 3/4 hp for a short period of time.Figure less than this for average, allow a little for "windage" , and 2 hp should be more than adequate, if geared properly.You should also be able to increase the speed at this power level, without concern of overload.Always pays to have a little power left over for change in grade, load, etc.

Using a lining bar a human can move a train car weighing many times 2.5 tons. So make sure that leverage aids are not being employed.

Getting the car moving is the hard part as static friction is higher than kinetic. Watching horse pulling contests, a horse can start and pull about twice its weight. Humans should be able to do at least the same (push/pull twice their weight without excessive straining, if they can get good footing).

In the original post, I think it can be taken that the 2 blokes are not levering the truck along - this would be ridiculous (unless they're pedalling or equivalent - in which case the poster should have been more specific).

For the solution, isn't a gearbox a leverage aid?

Your really need to know more about the men who are doing the job at present.

1. Is it the boss or owner of the business who is pushing or motivating the other guy?
2. Is the boss in the area when the pushing is being done?
3. Are the guys working on contract to get more meters per minute?