Blind Drivers????
1 - 20 of 24 Posts
Joined
·
4,961 Posts
It varied. It was common on locomotives designed to run on tighter curves or with longer wheelbases to make the center drivers blind. This was far less common on standard gauge locos, but not uncommon. Blind drivers were wider than the flanged drivers to compensate. PRR drawings show that their flanged drivers were 6" wide (including the flange) and 8" wide for the blind drivers. On the narrow gauge side of things, the wheels were a bit narrower, but there was still a difference. The EBT's flanged drivers were 5" wide, blind drivers 6".
Later,
K
Later,
K
Joined
·
6,296 Posts
Posted By CCSII on 04/04/2008 5:24 PM
Here I am approaching two thirds of a century old and I didn't realize that blind drivers were prototypical!
Are our models accurate (Connie - two blind drivers etc.?) What did the real RR's do?
The real railroads had the same problems. The Baltimore & Ohio had some particularly tight curves - which is what happens when you're the first guy on the block to get a train and you don't realise just how big them locos are going to get.
" border=0>" >
If you visit the B&O Railroad Museum in Baltimore (highly recommended) you'll find a 4-6-0, "Thatcher Perkins" which looks like this (click on the second thumbnail of the 4-6-0):
http://www.toytrains1.com/museum-bo.htm
If you look really closely, you'll see the tires on the front two drivers look a bit thicker than the one on the back. That's because this loco had blind drivers on the front two axles. /DesktopModules/NTForums/themes/mls/emoticons/w00t.gif" border=0>" border=0>
Unlike most 4-6-0 types, the front pilot truck has a rigid pivot and that keeps the drivers over the rails. (Most 4-6-0s have a pilot that can move from side to side, as the drivers have flanges.)
You will also find the 4-4-0, "William Mason", which looks like this:
![]()
(Here disguised as 'Wanderer' for the Wild Wild West movie.) It also is missing the flanges on the front drivers.
Here I am approaching two thirds of a century old and I didn't realize that blind drivers were prototypical!
Are our models accurate (Connie - two blind drivers etc.?) What did the real RR's do?
The real railroads had the same problems. The Baltimore & Ohio had some particularly tight curves - which is what happens when you're the first guy on the block to get a train and you don't realise just how big them locos are going to get.
" border=0>" >If you visit the B&O Railroad Museum in Baltimore (highly recommended) you'll find a 4-6-0, "Thatcher Perkins" which looks like this (click on the second thumbnail of the 4-6-0):
http://www.toytrains1.com/museum-bo.htm
If you look really closely, you'll see the tires on the front two drivers look a bit thicker than the one on the back. That's because this loco had blind drivers on the front two axles. /DesktopModules/NTForums/themes/mls/emoticons/w00t.gif" border=0>" border=0>
Unlike most 4-6-0 types, the front pilot truck has a rigid pivot and that keeps the drivers over the rails. (Most 4-6-0s have a pilot that can move from side to side, as the drivers have flanges.)
You will also find the 4-4-0, "William Mason", which looks like this:
(Here disguised as 'Wanderer' for the Wild Wild West movie.) It also is missing the flanges on the front drivers.
Joined
·
137 Posts
As Pete pointed out the B&O was a big fan of blind drivers in the early days. In addition to the Thatcher Perkins and William Mason the "Davis Camel" and JC Davis also feature blind drivers. As engineer of the Mason I can tell you that the blind drivers actually cause operational problems on modern track as they are too wide for "self garded" frogs and we have to slow waaay down as the blind driver will hit it and "thump" to the side. When you're dealing with a 152 year old frame you want to minimize "thumping."
Joined
·
6,296 Posts
When you're dealing with a 152 year old frame you want to minimize "thumping."
In my humble opinion, when you're dealing with a unique 152-year-old working steam loco, you want to eliminate thumping!!
In my humble opinion, when you're dealing with a unique 152-year-old working steam loco, you want to eliminate thumping!!
Joined
·
5,510 Posts
Only some of the drivers are flangeless, usually the middle ones. The others act to keep the loco on the rails.
Joined
·
4,961 Posts
So long as there were enough flanges to keep the wheels over the rails, then this wasn't an issue. Since they tended to be a bit wider, than the flanged drivers, there was an added safety net.
![]()
First and forth axles have flanged drivers. The middle drivers hang over the rails by a considerable amount, but are still on top of it.
Later,
K
First and forth axles have flanged drivers. The middle drivers hang over the rails by a considerable amount, but are still on top of it.
Later,
K
Joined
·
759 Posts
I've always wondered what happened if you tried to go around a curve that was too sharp with a blind driver. Granted, it "shouldn't" happen, but I'm sure somebody said "Hey, it'll be OK if we go reeeel slow." I know that a flanged driver could turn a rail over, or possibly jump up over the rail and down the other side, but are there any cases known where a blind driver fell off the rail because the curve was too sharp for the tread?
Joined
·
388 Posts
Kenneth,
Southern Pacific would not allow blind driver locomotives over Donner Pass in the Sierra Nevada mountains for just that reason (dropping off the rails on the inside). All of their locomotives over that pass had all drivers flanged including the 4-8-8-2 cab forwards.
Best regards,
Alan
Southern Pacific would not allow blind driver locomotives over Donner Pass in the Sierra Nevada mountains for just that reason (dropping off the rails on the inside). All of their locomotives over that pass had all drivers flanged including the 4-8-8-2 cab forwards.
Best regards,
Alan
Joined
·
55 Posts
Hello friends. Re Blind Drivers, The British Railways class 9F 2-10-0 and the WD 2-10-0 had the centre wheelsets flangeless and in some locations were restricted because the flangeless wheels would drop in as in Thornaby Motive Power Depot (51L) on the reverse curve up to the point to reverse into the roundshed (Bullring) We did have some blind drivers who sometimes were looking were the engine wasn't going and finished up (down) in the outside turntable hole! Circa 1958/9 I do have a photo of the damaged turntable somewhere.
In Germany the class 55 and 56 engines had some of the wheelsets with thinner flanges.
In the early days the brake blocks were made of wood and the men of steel but later on in life the brakeblocks were made of steel and the enginemen ......... .(I jest)
Jim Brodie ex steam engine cleaner.
In Germany the class 55 and 56 engines had some of the wheelsets with thinner flanges.
In the early days the brake blocks were made of wood and the men of steel but later on in life the brakeblocks were made of steel and the enginemen ......... .(I jest)
Jim Brodie ex steam engine cleaner.
Joined
·
4,961 Posts
JB, the only Aristo loco with blind drivers that I know of is the C-16, and they touch. So far as I know, they always have, back to the first Delton version. As for Bachmann, the only loco with a blind driver that doesn't touch is the 4-6-0. Everything else has a sprung suspension, so they contribute to the pulling as they should.
Later,
K
Later,
K
Blind centre drivers seem to have been fairly common in Europe. The Polish 60cm gauge 350hp LYD2 0-6-0 diesel hydraulics and narrow gauge O&K 0-6-0 steam classes both have a flangeless centre driver.
In Ireland there is a theory that the Lough Swilley 4-8-0 and 4-8-4T locos were originally built with flangeless leading drivers, but were later moved to the second axle visible in most photographs.
In practice the coned profile of the tyre keeps a wheelset running on the track, the flange only comes in to play on tight curves or through switches and crossings. So in theory even a leading flangeless wheelset should stay on.
John
In Ireland there is a theory that the Lough Swilley 4-8-0 and 4-8-4T locos were originally built with flangeless leading drivers, but were later moved to the second axle visible in most photographs.
In practice the coned profile of the tyre keeps a wheelset running on the track, the flange only comes in to play on tight curves or through switches and crossings. So in theory even a leading flangeless wheelset should stay on.
John
Joined
·
6,296 Posts
a blind driver fell off the rail
I should point out that the blind drivers have much wider tires than a normal wheel. On my photo of Wanderer, the shadow of the front wheel is much more pronounced due to the double-wide tire!
in theory even a leading flangeless wheelset should stay on
Interesting theory - better you try it than me.
I should point out that the blind drivers have much wider tires than a normal wheel. On my photo of Wanderer, the shadow of the front wheel is much more pronounced due to the double-wide tire!
in theory even a leading flangeless wheelset should stay on
Interesting theory - better you try it than me.
Joined
·
55 Posts
I may be tryimg to teach my grandmother to suck eggs but I thought the cone ing on a wheel was for curves.?. On straight track the wheels would or should run true and centrally. If not then that pair of wheels in trying to run evenly would "hunt" that is move side to side .
This caused wagons to oscillate and if it was a Brake Van the guard could get a rough ride. In my early days on the railway if we were travelling passenger to collect a train or coming home pass' and if it should be a goods train to travel on-IF the guard had a tow rope coiled round on the van floor you went for another train as that van would be a rough rider and when moving the guard would sit on the van floor on the coiled tow rope to try and make the journey easier(Honest)....back to the tyre profile.
two wheels on a steel axle -the wheels turning movement are the same -yes?-when we come to a curve the wheel on the inner curve should turn slightly less than the wheel on the outer curve-as the tyre is coned the wheels slew into the outer rail and the larger diameter of the tyre comes into effect. At the same time the inner wheel is now riding on the smaller part of the cone and this allows a fixed axle to turn and not twist or the wheel set slide or judder or "hunt"
In America note some of the steam engine tenders had a dummy gangway to try and improve the riding quality of the head end cars providing these cars or passenger vehicles had gangways as well.
On the british scene sometimes a fully brake fitted freight ie fish from Aberdeen to London then it was permissable for one or two
"swingers" to be coupled behind the van so steadying any oscillation that might set up on the van if it was the rear vehicle.
We tended to call a Goods Brake Van which the train guard rode in simply as a Van. Engine and Van or from the guard to the driver
You have fiftyfour and a van on or whatever the load was plus any other instructions say what the maximum speed would be of the slowest vehicle or if a braked train on air brakes whether the train was two pipe or single pipe and so on.
At our depot when I was o the footplate our trains were loose coupled,that is coupled by three link coupling and only brake was the engine steam brake sometimes on long gradients down the tender hand brake would be wound on a few turns to hold the buffers together and not knock the guard up.
I know I was a steam engine cleaner....Jim brodie.
This caused wagons to oscillate and if it was a Brake Van the guard could get a rough ride. In my early days on the railway if we were travelling passenger to collect a train or coming home pass' and if it should be a goods train to travel on-IF the guard had a tow rope coiled round on the van floor you went for another train as that van would be a rough rider and when moving the guard would sit on the van floor on the coiled tow rope to try and make the journey easier(Honest)....back to the tyre profile.
two wheels on a steel axle -the wheels turning movement are the same -yes?-when we come to a curve the wheel on the inner curve should turn slightly less than the wheel on the outer curve-as the tyre is coned the wheels slew into the outer rail and the larger diameter of the tyre comes into effect. At the same time the inner wheel is now riding on the smaller part of the cone and this allows a fixed axle to turn and not twist or the wheel set slide or judder or "hunt"
In America note some of the steam engine tenders had a dummy gangway to try and improve the riding quality of the head end cars providing these cars or passenger vehicles had gangways as well.
On the british scene sometimes a fully brake fitted freight ie fish from Aberdeen to London then it was permissable for one or two
"swingers" to be coupled behind the van so steadying any oscillation that might set up on the van if it was the rear vehicle.
We tended to call a Goods Brake Van which the train guard rode in simply as a Van. Engine and Van or from the guard to the driver
You have fiftyfour and a van on or whatever the load was plus any other instructions say what the maximum speed would be of the slowest vehicle or if a braked train on air brakes whether the train was two pipe or single pipe and so on.
At our depot when I was o the footplate our trains were loose coupled,that is coupled by three link coupling and only brake was the engine steam brake sometimes on long gradients down the tender hand brake would be wound on a few turns to hold the buffers together and not knock the guard up.
I know I was a steam engine cleaner....Jim brodie.
Joined
·
5,510 Posts
Except for blind drivers I have never seen a wheel on any railed vehicle that was not coned or tapered (outer diameter smaller than the inner/flanged side diameter).
If the wheel treads are straight (not tapered) then one side will be larger than the other due to manufacturer tolerances and after a few miles just wear alone will cause different diameters. This will cause the axle/wheel set to move one way or the other until the flange on that side contacts the rail head, where it will bounce off with quite a jar to the occupants of the vehicle and cause tremendous wear on the railhead and the flange.
The taper is 1 in 20 on every drawing I can find ("1941 Locomotive Cyclopedia", "1906 Locomotive Dictionary", "The Steam Locomotive Study Course", etc.). Attached is a drawing from the "1922 Car Builders Cyclopedia" showing the dozen or so dimensions of the wheel profile specification.
The feelings conveyed by any "hunting" that goes on in a passenger vehicle should be damped by the wheel truck to body bolsters.
If the wheel treads are straight (not tapered) then one side will be larger than the other due to manufacturer tolerances and after a few miles just wear alone will cause different diameters. This will cause the axle/wheel set to move one way or the other until the flange on that side contacts the rail head, where it will bounce off with quite a jar to the occupants of the vehicle and cause tremendous wear on the railhead and the flange.
The taper is 1 in 20 on every drawing I can find ("1941 Locomotive Cyclopedia", "1906 Locomotive Dictionary", "The Steam Locomotive Study Course", etc.). Attached is a drawing from the "1922 Car Builders Cyclopedia" showing the dozen or so dimensions of the wheel profile specification.
The feelings conveyed by any "hunting" that goes on in a passenger vehicle should be damped by the wheel truck to body bolsters.
Joined
·
55 Posts
I believe there was a slight differance to the coning on the LMS as a lay man once commented on this in the 40s that the LMS vehicles gave a better ride, I am prejudiced being an NER man but other railways could and did have good things as well. As for the GWR---(sorry I couldn't find a font small enough to print them three letters and I had to go outside after typing what I did as Modom won't let me spit indoors!)
I will try and find the LMS specs when I find my specs.
Jim Brodie potential steam engine cleaner.
I will try and find the LMS specs when I find my specs.
Jim Brodie potential steam engine cleaner.
1 - 20 of 24 Posts
Join the discussion
Join now to ask and comment!