ZU eave roofs (was NYRB Ventilated cars mysteries)


Dennis Storzek
 

On Tue, Sep 18, 2018 at 01:01 PM, rwitt_2000 wrote:
In fact the B&O 40-ft box cars kits for M-66 and M-67 had a IH of 10'-0" and so stenciled.
I think that Tim is remembering seeing a sectional view of the pressed "ZU" side plate, and noticed it is taller than the typical Z bar eave. However, there were roof panels meant to rivet to the Z bar manufactured with a couple different dimensions of the upright leg, and there were also custom pressed Z plates with a taller than normal flange; I believe some road had 10'-8" IH cars built this way.

To my mind, the significant feature of the "overhanging" roof panels is that both heads of the attachment rivets are outside the car. I doubt repairing cars under load was a big consideration, but when it came to insulated cars, that feature meant that roofs could be repaired without removing the lining and insulation to access the rivet heads that would otherwise be inside the car. The labor savings would be significant. 

When one looks at drawings of some of the first steel reefers from the thirties, one finds this was originally accomplished by riveting an angle to the upper flange of the standard Z bar used as the side plate, then riveting the roof panels to the angle. The custom pressed "ZU" section came later.

Dennis Storzek


rwitt_2000
 

Tim,

In fact the B&O 40-ft box cars kits for M-66 and M-67 had a IH of 10'-0" and so stenciled.




Bob Witt


Dennis Storzek
 

How so, Tim?

Dennis Storzek


Tim O'Connor
 


I always thought another reason for the preference was that you got an extra 1"
or so of interior height. Is that wrong?

Tim O'



Dennis Storzek wrote "ZU eaves were preferred on newly built insulated cars, because all the roof fasteners are external, and a roof can be repaired while the car is under load. It wasn't mandatory, however, and some RB's had the normal roof panels applied to Z bar eaves. The trade off was the car had to be unloaded and the ceiling opened up to repair a damaged roof."


 Dennis your comment is the first time I recall reading why there maybe a preference for "ZU" eaves.
 The B&O started using "ZU" eaves on box cars, non-insulated, with the kits ordered from ACF and P-S
 for their class M-66 and M-67, respectively.
 Thanks,
 Bob Witt


--
Tim O'Connor
Sterling, Massachusetts