Internal Combustion

Castenea wrote:

n7axw wrote:
Diesels produce torque more efficiently than steam given the same fuel expenditure. Your post is right on.

Don

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I would not be so sure. Internal combustion has a very different torque curve than external combustion. Steam pistons produce their greatest torque at stall and steam tractor always pull farther than diesels (who pull farther than gasoline) at tractor pulls.

https://www.youtube.com/watch?v=XhgHrDbN4EUUP 3985 leading 143 double stacked containers

Could this be related to their weight? The UK railways had no problem with drive wheels slipping in wet Autumn weather because of leaves on the lines until the (lighter) diesel-electric engines were introduced. As I understand it, the steam engines were heavy enough to destroy leaf structure completely at the points where the drive wheels contacted the rails, whereas the lighter engines left enough of the leaf to act as a lubricant.
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Peter2 wrote:
Could this be related to their weight? The UK railways had no problem with drive wheels slipping in wet Autumn weather because of leaves on the lines until the (lighter) diesel-electric engines were introduced. As I understand it, the steam engines were heavy enough to destroy leaf structure completely at the points where the drive wheels contacted the rails, whereas the lighter engines left enough of the leaf to act as a lubricant.
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Most UK steam locomotives had sanding gear, frequently steam operated, to provide additional adhesion as well as an axle loading up to 23 (long) tons (51,520 lbs for US engineers)on the driving axles.

The driving wheels for passenger locomotives were usually 5'6" or greater (up to 6'8½") which also helps minimise slipping, compared with the 3'6" max diameter of "Modern Traction" rolling stock.

The Blaisdell engine ran on natural gas with a hot tube ignition and no timing gears. A small one could be hand started and run a compressor to start a large one. Lots of info on the web.
Once precision metrology and machine technology is developed conventional diesel injectors, fuel pumps, and engine blocks are possible. All without electricity.
BTW - The Blaisdell business now makes Zip po lighters.

chrisd wrote:

Peter2 wrote:
Could this be related to their weight? The UK railways had no problem with drive wheels slipping in wet Autumn weather because of leaves on the lines until the (lighter) diesel-electric engines were introduced. As I understand it, the steam engines were heavy enough to destroy leaf structure completely at the points where the drive wheels contacted the rails, whereas the lighter engines left enough of the leaf to act as a lubricant.
.

Most UK steam locomotives had sanding gear, frequently steam operated, to provide additional adhesion as well as an axle loading up to 23 (long) tons (51,520 lbs for US engineers)on the driving axles.

The driving wheels for passenger locomotives were usually 5'6" or greater (up to 6'8½") which also helps minimise slipping, compared with the 3'6" max diameter of "Modern Traction" rolling stock.

Venting steam from the pistons water drains onto the track helps too.

Peter2 wrote:Could this be related to their weight? The UK railways had no problem with drive wheels slipping in wet Autumn weather because of leaves on the lines until the (lighter) diesel-electric engines were introduced. As I understand it, the steam engines were heavy enough to destroy leaf structure completely at the points where the drive wheels contacted the rails, whereas the lighter engines left enough of the leaf to act as a lubricant.

chrisd wrote:Most UK steam locomotives had sanding gear, frequently steam operated, to provide additional adhesion as well as an axle loading up to 23 (long) tons (51,520 lbs for US engineers)on the driving axles.

The driving wheels for passenger locomotives were usually 5'6" or greater (up to 6'8½") which also helps minimise slipping, compared with the 3'6" max diameter of "Modern Traction" rolling stock.

AirTech wrote:Venting steam from the pistons water drains onto the track helps too.

Sorry gents, but I have to put my rail enthusiast hat on here. All of these theories are wrong.

I don't want to go into the individual fallacies I've quoted, I'm not diplomatic enough not to offend doing so.

Steam locos slip; they always have. Modern traction power units slip; they always will. The difference is that modern customers demand answers for 'unacceptable' service that our grandparents would have found quite satisfactory, and then misinterpret the perfectly reasonable (but technical, and often simplified by the PR department past the point an engineer would recommend even before the media gets hold of them) explanations they finally receive.

The infamous 'leaves on the line' thing comes from two factors which happened to come to a head at about the same time:
First, there is a thing we rail enthusiasts like to not mention, called 'lineside fires'. These can be bad, for multiple reasons, but they do have one very good side effect: no lineside vegetation. Twenty-thirty years after the last regular steam trains have gone by, the trees alongside the railway will have grown up and over far enough to drop their leaves directly on the rails, instead of well clear of the trackbed. Damp leaves, a little bit of sand from the sanders, crush under the steel wheels, and you have an absolutely wonderful lubricant-come-grinding paste that actually sticks to the wheel treads.
The second issue is the transition, for good and proper reasons, from traditional railway clasp brakes (which bear on the wheel rims) to disk brakes (which bear on either the body of the wheels themselves or on separate disks mounted on the axles). Disk brakes work great, but they don't clean the wheels...