Alco RS11 modeling project - dynamic brake details

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lupilup

Alco RS11 modeling project - dynamic brake details

Post by lupilup »

Hello to all Alco fans!

As a model railroader from Germany I recently fell in love with the Alco RS11. I'm modeling in 1:29 scale and there is no RS11 on the market. So I decided to scratchbuild one. The powered AAR type B road trucks are offered as replacement parts from Aristocraft (used on their RS3, U25B and Alco FA1). I found many photos on the internet and some scale drawings from side shots but I wasn't able to find blueprints. My special question to you is if someone can show me detail shots from the dynamic brakes. I couldn't recognize if there should be grids over the outlets. I looked on photos of the RSD12, RSD15, C424 and C425 that may have similar ones but couldn't find photos that showed the roof details close enough. Blueprints would also be very appreciated.

Rolf

Paul
Posts: 648
Joined: Fri Mar 12, 2004 10:58 am
Location: EAST OF EDEN

Post by Paul »

I am going to work on an Rs-32 on Saturday, 4-14-07. I will be pulling the fans off the dynamic brake grid blower motor. The hatch is on the ground so I can get as many pictures and measurements as you wish. You will need to convert them to metric. I hope this will help.
Paul
"We are all here because we are not all there."

lupilup

Post by lupilup »

Paul, thank you very much :-D ! Converting the measurements to metric is no problem. Detail pics would be very helpfull.

tgibson
Posts: 104
Joined: Tue Mar 16, 2004 6:33 pm
Location: San Diego

Post by tgibson »

Hi,

Here is an RS-11 roof shot - there are parallel grates over the DB openings:

Image

Hope this helps,
Tom Gibson

Cal Classic Alco Page: http://www.calclassic.com/alco/

lupilup

Post by lupilup »

Tom, thank you! That is a first help. I already had found this picture but could not figure out what is there exactly over the openings.

Further questions: Are those openings square holes? Are the resistors of the brake cooled only by air? Where is the air inlet?

Rolf
Last edited by lupilup on Sat Apr 14, 2007 7:43 am, edited 1 time in total.

lupilup

Post by lupilup »

Hello Paul and Tom! I made a schematic drawing (not to scale,viewed from top) of what I think it should look like.

<img src="http://www.lupilup.com/grafiken/dynamciRS11.jpg">

Rolf

Typewriters
Posts: 278
Joined: Fri Mar 12, 2004 8:29 pm

Post by Typewriters »

Image


Note lower, side view showing internals of dynamic brake resistor and blower assembly. Air taken in at center, and can go thru either blower fan thru the resistor grids; directed by baffles up through square exhaust vents as shown in roof view and in photo previously posted.

-Will Davis

lupilup

Post by lupilup »

Will, thank you very much! Those drawings will be a very big help for me building my model. :-D

Paul
Posts: 648
Joined: Fri Mar 12, 2004 10:58 am
Location: EAST OF EDEN

Post by Paul »

As promised, and I hope these help:
Image
Image
Image
Image
Image
Image

Now, anybody know here I can borrow a puller, GE part number 675399G4 & G2 so I can remove the fan and bearings from a 5GY19PA3 blower motor?
Paul
"We are all here because we are not all there."

lupilup

Post by lupilup »

Paul, this helps very much. With the drawings from Will, the description from Tom and your detailed photos there won't be any question left and I won't have problems building the dynamic brake unit for my model.

Thanky you all!

Rolf

Paul
Posts: 648
Joined: Fri Mar 12, 2004 10:58 am
Location: EAST OF EDEN

Post by Paul »

By the way, the set back for the exhaust vents are 2.5 inches from the end and 5.75 inches from the sides. They are 15X31.5 inches.The air intake (center) vent openings are 34.5 X 2.75 inches. Total length of the hatch is 134.5 X 48 inches. The hight of the air hatch at the centerline on the roof is 2.5 inches
Paul
"We are all here because we are not all there."

tgibson
Posts: 104
Joined: Tue Mar 16, 2004 6:33 pm
Location: San Diego

Post by tgibson »

Hi,

BTW, the expanded metal over the top openings were added sometime after delivery (to keep people from stepping on the grates).

Also, I think the air intakes on the sides at the middle of the unit were also added later.

Hope this helps,
Tom Gibson

Cal Classic Alco Page: http://www.calclassic.com/alco/

Typewriters
Posts: 278
Joined: Fri Mar 12, 2004 8:29 pm

Post by Typewriters »

I think we have some different housings shown in the various pictures and drawings.

A close look at the operating manual for RS-11 and RSD-12 locomotives reveals that the dynamic brake housings are different; note on the drawings I've linked that the housing, between the air outlets, has two panels. The RSD-12 housing is longer and has three panels. Neither has any sort of air intake above the roofline at the center. The detail internal view of the dynamic brake housings clearly reveals a larger number of resistor grids inside the (longer) housing on the (six-axle) RSD-12 as compared with the (four-axle) RS-11.

The operating manual for Century series locomotives (in this case C-420) shows what appears to be a dynamic brake housing identical to that pictured removed from the RS-32; namely, three sections with side intakes above the roofline.

I do rather think, then, that the color photos (which are excellent by the way and the first I've ever seen anywhere) showing the complete housing removed do not apply to the RS-11, at least early (publishing date of the manual I scanned the drawing from is Feb. 1956) and probably apply to RS-32 and later (and probably RS-36.)

-Will Davis

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