Date
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Staff brake wheel height
destorzek@...
---In STMFC@..., <therrboomer@...> wrote :
Was there a standard height requirement for a staff brake wheel above the platform? For staff brake with no platform what was wheel height above car roof line?
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Not that I'm aware of. The "Standard Safety Appliances for Box and Other House Cars" drawing published in the 1922 Car Builder's Cyclopedia only shows two critical dimensions:
1) There must be a minimum of 4" clearance, both vertivcally and horizontally, between the handwheel and any obstruction
2) The rim of the handwheel cannot be closer than 4" to the plane through the coupler pulling face.
Everything else was left to the discretion of the railroad or car builder.
Dennis Storzek
It's interesting that in most photos the staff brake wheel is
the HIGHEST point on the car! As cars got taller and pushed the
limits of clearances, I wonder if that had a lot to do with
moving the brake wheels to the end of the car.
Tim O'
Was there a standard height requirement for a staff brake wheel above the platform? For staff brake with no platform what was wheel height above car roof line?
===================
Not that I'm aware of. The "Standard Safety Appliances for Box and Other House Cars" drawing published in the 1922 Car Builder's Cyclopedia only shows two critical dimensions:
1) There must be a minimum of 4" clearance, both vertivcally and horizontally, between the handwheel and any obstruction
2) The rim of the handwheel cannot be closer than 4" to the plane through the coupler pulling face.
Everything else was left to the discretion of the railroad or car builder.
Dennis Storzek
Richard MCQUADE
In Mainline Modeler Feb. 1996 there was an article by Keith Retterer about safety appliances. There are drawings of the 1911 Safety Appliance standards but my scanned copy of the magazine doesn't show the dimensions clearly enough. Maybe another member of the group has this issue and can check the dimensions for you.
Richard
Richard
Scott H. Haycock
I have that issue of MM.
Other than the 4'' clearance mentioned by Dennis, there are no other dimensions related to the brakewheel's position. The brake staff must be within 17''-22'' of the vertical centerline of the end of the car.
Scott Haycock
In Mainline Modeler Feb. 1996 there was an article by Keith Retterer about safety appliances. There are drawings of the 1911 Safety Appliance standards but my scanned copy of the magazine doesn't show the dimensions clearly enough. Maybe another member of the group has this issue and can check the dimensions for you.
Richard
Group,
There is no standard height for a Plate A staff hand brake but it is easy to calculate what is would be for any specific car series. Just go to an ORER and look up the series. Subtract extreme height from height to running board.and that gives you the height of the brake shaft above that point for those that are equipped with staff brakes. Easy.
Don't forget that there is a nut on the shaft!
Dan Smith
There is no standard height for a Plate A staff hand brake but it is easy to calculate what is would be for any specific car series. Just go to an ORER and look up the series. Subtract extreme height from height to running board.and that gives you the height of the brake shaft above that point for those that are equipped with staff brakes. Easy.
Don't forget that there is a nut on the shaft!
Dan Smith
Tim,
Short answer to your implied question, no.
The move to vertical wheel geared power hand brakes was the result of the shake out of various attempts to increase braking force that was needed because of the rapid increase in car weight, not car height.
Compound lever or compound pulley systems under the car and various geared contraptions attached to the brake shaft either at the bottom or top of the car end dating to the teens and before are common. With the introduction of the Ajax vertical wheel geared power hand brake in the mid '20's, quickly followed by other manufacturers, the advantages of this format won out. In all cases, these systems trade distance - the spin of the wheel - for force exerted on the brake lever at the end of the cylinder under the car.
There are many examples of what would be considered tall cars, various 50' SS autocars from the late '20's come to mind, that still used Plate A staff brakes. Well after the availability of end of car geared power hand brakes. A late example of what at the time would be considered a tall, general interchange house car using a Plate A staff brake is the GN 50000 to 50999 series DS box cars of 1937. I'm sure we could all come up with others.
Dan Smith
Short answer to your implied question, no.
The move to vertical wheel geared power hand brakes was the result of the shake out of various attempts to increase braking force that was needed because of the rapid increase in car weight, not car height.
Compound lever or compound pulley systems under the car and various geared contraptions attached to the brake shaft either at the bottom or top of the car end dating to the teens and before are common. With the introduction of the Ajax vertical wheel geared power hand brake in the mid '20's, quickly followed by other manufacturers, the advantages of this format won out. In all cases, these systems trade distance - the spin of the wheel - for force exerted on the brake lever at the end of the cylinder under the car.
There are many examples of what would be considered tall cars, various 50' SS autocars from the late '20's come to mind, that still used Plate A staff brakes. Well after the availability of end of car geared power hand brakes. A late example of what at the time would be considered a tall, general interchange house car using a Plate A staff brake is the GN 50000 to 50999 series DS box cars of 1937. I'm sure we could all come up with others.
Dan Smith
destorzek@...
Very well put. One thing that's is not obvious about "high power" geared hand brakes is you have to move the brake wheel more revolutions to have the same effect; something that I'm sure got old fast with a horizontal wheel above the car roof. The Ajax gear, and most of those that followed, were designed to take up the slack by giving the wheel one good spin and letting it freewheel until it met resistance from the brake rigging.
The other thing to note is the clearance diagram has always been a rectangle with the upper corners clipped off, in deference to the shape of arched tunnel linings and the like. Therefore the limit to car height has always been the height at the corners... there has always been extra room over the center of the car. In modern (future) times, the shape of enclosed auto racks just fills the clearance diagram.
Dennis Storzek
---In STMFC@..., <espeefan@...> wrote :
The other thing to note is the clearance diagram has always been a rectangle with the upper corners clipped off, in deference to the shape of arched tunnel linings and the like. Therefore the limit to car height has always been the height at the corners... there has always been extra room over the center of the car. In modern (future) times, the shape of enclosed auto racks just fills the clearance diagram.
Dennis Storzek
---In STMFC@..., <espeefan@...> wrote :
Tim,
Short answer to your implied question, no.
The move to vertical wheel geared power hand brakes was the result of the shake out of various attempts to increase braking force that was needed because of the rapid increase in car weight, not car height.
Compound lever or compound pulley systems under the car and various geared contraptions attached to the brake shaft either at the bottom or top of the car end dating to the teens and before are common. With the introduction of the Ajax vertical wheel geared power hand brake in the mid '20's, quickly followed by other manufacturers, the advantages of this format won out. In all cases, these systems trade distance - the spin of the wheel - for force exerted on the brake lever at the end of the cylinder under the car.
There are many examples of what would be considered tall cars, various 50' SS autocars from the late '20's come to mind, that still used Plate A staff brakes. Well after the availability of end of car geared power hand brakes. A late example of what at the time would be considered a tall, general interchange house car using a Plate A staff brake is the GN 50000 to 50999 series DS box cars of 1937. I'm sure we could all come up with others.
Dan Smith
Short answer to your implied question, no.
The move to vertical wheel geared power hand brakes was the result of the shake out of various attempts to increase braking force that was needed because of the rapid increase in car weight, not car height.
Compound lever or compound pulley systems under the car and various geared contraptions attached to the brake shaft either at the bottom or top of the car end dating to the teens and before are common. With the introduction of the Ajax vertical wheel geared power hand brake in the mid '20's, quickly followed by other manufacturers, the advantages of this format won out. In all cases, these systems trade distance - the spin of the wheel - for force exerted on the brake lever at the end of the cylinder under the car.
There are many examples of what would be considered tall cars, various 50' SS autocars from the late '20's come to mind, that still used Plate A staff brakes. Well after the availability of end of car geared power hand brakes. A late example of what at the time would be considered a tall, general interchange house car using a Plate A staff brake is the GN 50000 to 50999 series DS box cars of 1937. I'm sure we could all come up with others.
Dan Smith
destorzek@...
---In STMFC@..., <espeefan@...> wrote :
Don't forget that there is a nut on the shaft!
Dan Smith
==============
I'll say. I imagine the OP was really looking for some guidance as to height of the wheel over the roof, and placement of the brake step. I still have the builder's drawings of the NYC 36' car out, and they seem typical of common practice.
All dimensions shown for the height of the brake wheel are always to the top of the staff, since this is the point that has to stay within the clearance diagram. On the NYC cars this is 7-15/16" above the running board. The drawing of the brake wheel itself shows its hub to be 2" thick, with the rim 1" thick, putting the bottom of the rim 1-1/2" below the top of the hub. The nut and lock washer must take up 15/16", so the bottom of the wheel is 5-1/2" above the running board, slightly more than the ARA minimum of 4".
On the drawing of the wood sheathed end, the brake step is 2'-5" below the top of the running board, which would put it just about 3' below the brake wheel.
The steel end car is different... and the placement of the brake step is dimensioned relative to the grab irons rather than the running board, but chasing the dimensions on the drawing shows it to be 3-1/4" higher, putting it about 2'-9" below the brake wheel.
Dennis Storzek