MOPAC Brake Layout Question
|
Nelson Moyer
I’m ready to add the brake detail to my 81000 series modernized boxcar with AB brakes. The questions have to do with position of the air reservoir and the type of power hand brake to use. I have a left side photo of I-GN 14083 that clearly shows the control valve and brake cylinder, but not the air reservoir. That suggests that the air reservoir was mounted on the other side of the center sill. There is no vertical brake staff in the photo, so presumably, the car got power hand brakes. I also have a photo of MP 90000 with AB brakes showing the control valve, brake cylinder, and apparently a transversely mounted air reservoir on the right side of the center sill. The power hand brake isn’t visible on the B end.
What was MOPAC practice when converting cars with KC brakes to AB brakes re placement and orientation of the air reservoir? My pictures suggest that it was on the other side of the center sill from the control valve and brake cylinder, but I don’t know if transverse mounted air reservoirs were the norm. How should I mount the air reservoir on my 81000 series car?
What type of power hand brake did MOPAC use on these 1940s car conversions? Did they always install power hand brakes, or did some cars converted to AB brakes retain their vertical brake staffs?
Nelson Moyer |
|
|
|
Ed Hawkins
On Feb 11, 2017, at 10:09 AM, Nelson Moyer npmoyer@... [STMFC] <STMFC@...> wrote:
Sorry this reply is late. As MoPac upgraded SS box cars with power hand brakes, railroad diagrams designate Ajax and Universal as the two most used. A photo of 81322 taken 11-22-51, available from Bob’s Photo, shows an Ajax hand brake. The left-side photo also shows an AB brake cylinder, however, the reservoir on the opposite side of the center sill isn’t visible. Unfortunately, in-service photos of these cars are pretty sparse. Of the 1,000 auto cars 81000-81999 built in late 1924, roughly 1/4 of them continued service as auto cars beyond the period from 1936-1940 when MoPac converted approximately 722 of the remaining cars as XM single-door box cars 42000-42725. While I don’t have any other in-service photos of the 81000-series, photos of the 42000-series are more plentiful and provide information as to the reservoir position since the underframes were the same. Because these original auto cars had closely-spaced crossties near the door area, AB brake conversions had the reservoir mounted longitudinally farther from the cylinder than normal. The location was between two crossties spaced 53 1/4” apart with the crosstie nearest the “A” end bolster being 45 3/4” from the bolster center line. For this position, take a look at the right side of M.P. 42660 (a steel rebuild) on page 15 of RP CYC Vol. 14. The photos of M.P. 42005 provides a left-side view for the AB valve position that was also located near the “A” end truck. Regarding other MoPac 40’-6” SS box cars, there were basically two main types with one being a Howe-truss design with 3 sections on each side of the door. Due to wider crossbearer spacing on these cars, the longitudinal reservoir & AB valve were positioned more conventionally near the door. See photo of M.P. 46834 on page 21 of RP CYC Vol. 14. Conversely, the 90000-91249 (originally SS auto cars) and 93000-95249 SS XM box cars with 4 sections on each side of the door had narrower crosstie spacing such that AB brake upgrades had them positioned transversely on all of these cars. Numerous photos and a history about the cars were published in an 18-page article, Spring-Summer 2007 Eagle, available from the MPHS. Regarding the question about the timing of power hand brake and AB brake upgrades, they ranged from the mid-1930s well into the 1940s. I’ve seen photos showing every possible combination with both apparently occurring at the same time, AB brakes with a vertical-staff hand brake, and KC brakes with a power hand brake. In a few cases, cars with KC brakes came with a power hand brake. Hope this helps. Regards, Ed Hawkins |
|
|
|
Nelson Moyer
Thanks, Ed, for your authoritative and complete response to my questions. I have RP CYC Volume 14, so I’ll look up the photos. I forgot to ask about replacement of the wood doors with steel doors when AB brakes were added. Did any AB converted cars with one and a half doors retain wood doors up to 1953?
Nelson Moyer
From: STMFC@... [mailto:STMFC@...]
Sent: Thursday, February 16, 2017 10:52 PM To: STMFC@... Subject: Re: [STMFC] MOPAC Brake Layout Question
On Feb 11, 2017, at 10:09 AM, Nelson Moyer npmoyer@... [STMFC] <STMFC@...> wrote:
Nelson, Sorry this reply is late. As MoPac upgraded SS box cars with power hand brakes, railroad diagrams designate Ajax and Universal as the two most used. A photo of 81322 taken 11-22-51, available from Bob’s Photo, shows an Ajax hand brake. The left-side photo also shows an AB brake cylinder, however, the reservoir on the opposite side of the center sill isn’t visible. Unfortunately, in-service photos of these cars are pretty sparse.
Of the 1,000 auto cars 81000-81999 built in late 1924, roughly 1/4 of them continued service as auto cars beyond the period from 1936-1940 when MoPac converted approximately 722 of the remaining cars as XM single-door box cars 42000-42725. While I don’t have any other in-service photos of the 81000-series, photos of the 42000-series are more plentiful and provide information as to the reservoir position since the underframes were the same.
Because these original auto cars had closely-spaced crossties near the door area, AB brake conversions had the reservoir mounted longitudinally farther from the cylinder than normal. The location was between two crossties spaced 53 1/4” apart with the crosstie nearest the “A” end bolster being 45 3/4” from the bolster center line. For this position, take a look at the right side of M.P. 42660 (a steel rebuild) on page 15 of RP CYC Vol. 14. The photos of M.P. 42005 provides a left-side view for the AB valve position that was also located near the “A” end truck.
Regarding other MoPac 40’-6” SS box cars, there were basically two main types with one being a Howe-truss design with 3 sections on each side of the door. Due to wider crossbearer spacing on these cars, the longitudinal reservoir & AB valve were positioned more conventionally near the door. See photo of M.P. 46834 on page 21 of RP CYC Vol. 14.
Conversely, the 90000-91249 (originally SS auto cars) and 93000-95249 SS XM box cars with 4 sections on each side of the door had narrower crosstie spacing such that AB brake upgrades had them positioned transversely on all of these cars. Numerous photos and a history about the cars were published in an 18-page article, Spring-Summer 2007 Eagle, available from the MPHS.
Regarding the question about the timing of power hand brake and AB brake upgrades, they ranged from the mid-1930s well into the 1940s. I’ve seen photos showing every possible combination with both apparently occurring at the same time, AB brakes with a vertical-staff hand brake, and KC brakes with a power hand brake. In a few cases, cars with KC brakes came with a power hand brake. Hope this helps.
Regards, Ed Hawkins |
|
|
|
Ed Hawkins
On Feb 17, 2017, at 8:28 AM, Nelson Moyer npmoyer@... [STMFC] <STMFC@...> wrote: Thanks, Ed, for your authoritative and complete response to my questions. I have RP CYC Volume 14, so I’ll look up the photos. I forgot to ask about replacement of the wood doors with steel doors when AB brakes were added. Did any AB converted cars with one and a half doors retain wood doors up to 1953? Nelson, The Jan. 1953 ORER reported 247 cars remained in MP 81000-81999. The answer to your question about the doors is one of uncertainty. The MP diagram for the cars indicates “Camel Doors” (i.e., Youngstown), however, the one and only photo I have from close to this period (81322 taken in 1951) shows wood doors. The diagram provides no information as to a date when steel doors may have replaced the original wood doors. So my conclusion from the limited available information and just this one photo is that not all cars got the steel doors. While this may not apply to you, the 81000-series cars declined rapidly after July 1954 when the ORER reported 242 cars in revenue service. 125 in Oct. 1954 48 in Jan. 1955 31 in April 1955 20 in July 1955 9 in Jan. 1956 4 in April & July 1956 gone by Oct. 1956 Regards, Ed Hawkins |
|
|
|
Nelson Moyer
Thanks again, Ed. I bought the 81000 series car at a good price, hoping to be able to use it on my 1953 layout. From all the information you provided, I can build it with AB brakes, Ajax power hand brakes, and wood doors. I'll use the lettering style from the 81322 photo.
Nelson Moyer From: STMFC@... [mailto:STMFC@...] Sent: Friday, February 17, 2017 5:38 PM To: STMFC@... Subject: Re: [STMFC] MOPAC Brake Layout Question On Feb 17, 2017, at 8:28 AM, Nelson Moyer npmoyer@...<mailto:npmoyer@...> [STMFC] <STMFC@...<mailto:STMFC@...>> wrote: Thanks, Ed, for your authoritative and complete response to my questions. I have RP CYC Volume 14, so I'll look up the photos. I forgot to ask about replacement of the wood doors with steel doors when AB brakes were added. Did any AB converted cars with one and a half doors retain wood doors up to 1953? Nelson, The Jan. 1953 ORER reported 247 cars remained in MP 81000-81999. The answer to your question about the doors is one of uncertainty. The MP diagram for the cars indicates "Camel Doors" (i.e., Youngstown), however, the one and only photo I have from close to this period (81322 taken in 1951) shows wood doors. The diagram provides no information as to a date when steel doors may have replaced the original wood doors. So my conclusion from the limited available information and just this one photo is that not all cars got the steel doors. While this may not apply to you, the 81000-series cars declined rapidly after July 1954 when the ORER reported 242 cars in revenue service. 125 in Oct. 1954 48 in Jan. 1955 31 in April 1955 20 in July 1955 9 in Jan. 1956 4 in April & July 1956 gone by Oct. 1956 Regards, Ed Hawkins |
|
|