For those interested in old cars.

[APOLLO]

48 minutes ago, gordon s said:

Enjoyed watching that, but perhaps someone can explain something that has always puzzled me. Probably an easy answer, but blowed if I know.....

 

All couplings appear to be the same, but in the UK there is generally just one or two loco’s at the front. That means the first coupling behind the train has to be strong enough to withstand the weight of the whole train when pulling away from a standstill.
 

Are couplings and coupling mechanisms designed with a maximum weight in mind and as such all are engineered for a maximum weight. If you went beyond that point would the chain link stretch and break or the hook split into two? Maybe the hook pulls out of the buffer team?

 

Edit: I was thinking in terms of 3 link couplings not the modern versions

 

USA uses knuckle couplers, usually up for the job, occasionally one breaks parting the air brake hose and both sides of the break go into emergency braking & stop. The poor unfortunate Conductor (Guard)has to walk back & try to fix it - long walk as some trains are well over 100 cars long. With rear helpers there is a "floating" point where the front sections couplings are in tension and the rear in compression. A fine balancing act is required by the Engineer (Driver) - a very skilled man on this kind of train. And they are looking into one man operation on these trains !! (The rear helpers are sometimes radio controlled from the lead loco).

 

This is a good watch with the obligatory crazy (but helpful) railfan !!!!!!

 

 

Lots more on youtube - more than you would think (Though the USA is a pretty big place)

 

Brit15

Edited December 15, 2020 by APOLLO
typo

[Kickstart]

49 minutes ago, steve1 said:

 

And don't, as I once did, put so much weight in the boot of an Avenger it makes the steering dangerously light...

 

steve

A laden top box on a bike can have interesting side effects 

 

43 minutes ago, MrWolf said:

 

That drag tractor will have ridiculously low gearing, the reason his front wheels are lifting is that he is giving it the beans to go forward, but the steamer is dragging him and several tons of earth the opposite way.

Didn’t catch a part where the front wheels are lifting, but the angle of the join means that as it pulls the rear driving wheels are being lifted up, hence losing traction. And the traction engine weighs probably 6~7 times more, which gives plenty of traction.

 

Repeat this on concrete, with a load of ballast on the tractor and the towing arm parallel with the ground and things would likely be very different 

 

All the best

 

Katy

[MrWolf]

It's been done dozens of times at shows, the tractor gets pulled backwards into the ground (where it should have far greater wheel to ground contact) every time. They are ballasted and set up solely to pull an immense weighted sledge in tractor pulling contests. It's entirely about tractive effort, which the steam engine has masses of.

Some years ago a friend called round on his brand new Yamaha R1 and jokingly asked if I fancied a race? I pointed out that his bike was nearly 130hp and my 1946 BSA B31 was a mere 17hp, so did he fancy a tug of war instead? 

[Northmoor]

1 hour ago, Kickstart said:

Torque is just power divided by revs. So just use a lower gear to get torque at the wheels!

And don’t try and tow something which is lifting your driving wheels.

 

All the best

 

Katy

You're not wrong - obviously the maths works both ways - but strictly speaking it's the other way around, Power = Torque x Revs.  Torque generated is an inherent function of the engine design, while you can always put in a bit more fuel to make it rev harder to get to the same power figure (until it goes bang....).

[APOLLO]

Back to cars !!

 

 

Brit15

[Kickstart]

It is down to power and traction. Engine torque  isn’t important if you gear it right, as you can just add wheel torque. The tractor wheels are being pulled up, so just acting like an angle grinder spinning away through the dirt, and as it digs down the angle of the connector increases hence having more weight lifted at the back. Once traction is broken , game over.

 

They might well be ballasted, but nowhere near that much. Best I can make out the drag tractors are 3~4 tons in the heavy weight classes, , compared to, say, 22 tons for the traction engine.

 

Small front sprocket and the r1 would probably win the tug of war (stock gearing would be good for around 100mph in first), with plenty of wheel torque and traction

 

All the best

 

Katy

[Kickstart]

22 minutes ago, Northmoor said:

You're not wrong - obviously the maths works both ways - but strictly speaking it's the other way around, Power = Torque x Revs.  Torque generated is an inherent function of the engine design, while you can always put in a bit more fuel to make it rev harder to get to the same power figure (until it goes bang....).

Yep, of was being slightly free with the conversions.

 

Spent too much time working out wheel thrust against speed for bikes!

 

All the best

 

Katy

[MrWolf]

My mate didn't fancy finding out who would win a tug of war, something about possibly having to sweep his bike up afterwards. 

If we were to consider the relative centre of gravity of the two bikes, plus unsprung weight and the point of balance fore and aft, then your argument about the steam engines unfair advantage would come into play. The 350 single would then pull the new bike in half.

[Kickstart]

Well, convenient place to connect to the r1 would  be up just under the pillion seat. Given that most modern bikes look like the pillion needs a pilots licence, suspect pulling off it would lift up the bsa! However the seat unit isn’t that touch, as it only needs to hold the people, unlike the very tough main part of the frame.

 

Suspect the r1 centre of gravity is relatively far forward (on my fz750 it is ridiculously far forward!).

 

All the best

 

Katy

[MrWolf]

Are you seriously attempting to create a valid experiment and consequently score points out of something said in jest between friends??

 

Reminds me of when weekend wobblers ask questions like

 

"How fast does that dinosaur go then?"

 

The answer being:

 

"Fast enough to lose your license or kill yourself, which would you like to do?"

 

 

[big jim]

Fight, fight, fight!! 
 

 

[MrWolf]

15 hours ago, Enterprisingwestern said:

 

How old are you?!!!

 

Mike.

 

What he said.

 

 

Edited December 15, 2020 by MrWolf
SNAFU

[big jim]

Old enough to know better! 
 

 

[MrWolf]

1 hour ago, big jim said:

Old enough to know better! 
 

 

 

Do any of us actually live long enough to know better?

[skipepsi]

I never expected to reach 30 I am now 64 but buying another fast bike with my retirement pot might mean I don't reach 70. Short answer not me...

[MrWolf]

I plan on still being as daft when I hit that age. What else do you do? Give up everything to "act your age" and just sit around waiting for the undertaker?

[Enterprisingwestern]

23 minutes ago, MrWolf said:

I plan on still being as daft when I hit that age. What else do you do? Give up everything to "act your age" and just sit around waiting for the undertaker?

 

Always endeavour to be one step ahead of the undertaker, one day you will trip up!

 

Mike.

[Northmoor]

I came to the conclusion a few years ago that the joke: "A healthy lifestyle doesn't make you live longer, it just feels that way", actually has an element of truth.  I have had several relatives who led very different lifestyles and died at roughly the same age.  Not living an unhealthy lifestyle certainly does help; people die young from abusing their bodies with poor diet, smoking and drugs.  The people who've lived to 100 are always asked the same question in interviews by local press, "What's your secret?", but have you noticed how the answer is NEVER to have been living vegan diets, running 5km every week or as teetotallers their whole life, in fact they always seem to like the odd sherry or fish and chips once a week.  Meanwhile there are a lot of charlatans selling "healthy lifestyle" products hinting at an almost eternal life fantasy. 

The moral is: like a car your body has a design life.  Abuse it and it will become irrepairable earlier than you expect.  If you look after it, it will last its design life and maybe a little bit more, but no amount of excess care will prevent some parts failing after about the number of operating hours it was designed for.  Some people, like some cars, are just a lucky "design" and just seem to go on forever.

[boxbrownie]

10 hours ago, big jim said:

Old enough to know better! 
 

 

But not do better? 

[alastairq]

1 hour ago, MrWolf said:

Give up everything to "act your age" and just sit around waiting for the undertaker?

 I'm avoiding an undertaker altogether....my family have been told.....can o' petrol behind the garage, matches in kitchen drawer, and a shovel in the shed....Sorted!

Mind, that could always end up , by being stuffed into the brown bin?

[PhilJ W]

4 minutes ago, alastairq said:

 I'm avoiding an undertaker altogether....my family have been told.....can o' petrol behind the garage, matches in kitchen drawer, and a shovel in the shed....Sorted!

Mind, that could always end up , by being stuffed into the brown bin?

Just send me down to the glue factory when my turn comes.

[boxbrownie]

8 minutes ago, PhilJ W said:

Just send me down to the glue factory when my turn comes.

The thought of sticking my ballast down with your remnants sort of spoils my modelling ambitions oddly enough 

 

[Nick C]

16 hours ago, gordon s said:

Enjoyed watching that, but perhaps someone can explain something that has always puzzled me. Probably an easy answer, but blowed if I know.....

 

All couplings appear to be the same, but in the UK there is generally just one or two loco’s at the front. That means the first coupling behind the train has to be strong enough to withstand the weight of the whole train when pulling away from a standstill.
 

Are couplings and coupling mechanisms designed with a maximum weight in mind and as such all are engineered for a maximum weight. If you went beyond that point would the chain link stretch and break or the hook split into two? Maybe the hook pulls out of the buffer team?

 

Edit: I was thinking in terms of 3 link couplings not the modern versions

 

That's why 3-link and instanter couplings are loose (as opposed to screw links which are done up tight) - when the train stops, the couplings slacken, and the wagons all bunch up together. 

 

On restarting, the loco starts moving, takes up the slack on the first coupling, first wagon starts moving, takes up the slack on the second, etc - so you're only overcoming the initial friction on one wagon at a time. There's then a huge amount of skill needed from the driver to make sure he doesn't start to accelerate before the whole train is moving, otherwise the vehicles at the back get a massive jerk and the guard gets thrown off his feet!

 

There's also a lot of skill needed from the guard to keep the couplings taught when needed, and let them slacken when that's required...

Edited December 16, 2020 by Nick C

[johnlambert]

17 hours ago, APOLLO said:

Back to cars !!

 

 

Brit15

I appreciate this is stated tongue in cheek, but it simply isn't correct.  Momentum (or inertia) is what what will take the wall with you.

 

I also wish manufacturers or road testers would show the cascade graphs that show tractive effort versus road speed in each gear (plus a rising plot for the cumulative rolling and aerodynamic resistance with speed); these would be much more informative than power and torque curves.

[APOLLO]

My mate said he can tighten up nuts and bolts with his butt.

 

Personally I think he torques out of his arse

 

Brit15