Dynamic AS616

[WP 3020]

I've been looking for detail pictures of the top of  BLW AS616 sort hood dynamic brake (pref. SP but other roads will do). Ive seen some but were taken from a distance. From what I can tell, it looks like there were two kinds of fan placements or openings. One looks like a large rectangle opening covered with some kind of screen (was it expanded metal or grid type?) and the fans below. The other looks like two round (36 in.?) fans with shrouds on top like an early EMD F3 (but I can't see what the top of them looks like).
If anyone (maybee from Portola?) can recomend a book or post some pics. I would be very thankful.

[West Coast S]

No SP D/B equipped Baldwin ever had EMD inspired pan fans, although common to rebuilds of other roads, useually implied they were also re-engined with EMD's, no such animal existed on the SP.

Baldwin used what appears to be a large rectangular opening in the short hood, though the rivet battens between the grids concealed the fact that it was actually one continous piece. I can't say with authority what the grid material was, I doubt that any survived without being replaced with whatever was at hand..


Best of luck

Dave

[PBenham]

After going through my collection of locomotive manuals, here's the scoop on Baldwin AS-series Dynamic braking placement. The grids were mounted at the top of the short hood and were cooled by a single fan below the grids. This same system is used by GE today. The big drawback to this was that on a Baldwin AS16,616 or 416 There was no protection from flash-overs for crewmen walking by the short hood, while the unit was in dynamic braking. As such, PRR forbade employees from going by the grids while the unit was in dynamic braking mode.( Quote: "Employees on class BS16m, and/ or BS16ms, shall not pass by dynamic brake grids on front hood while the locomotive is in dynamic braking.")

[Mimbrogno]

Your right in that the shrouded versions are diffinatly not EMD inspired (That's sacralige!). Although I have not seen one myself, I believe that the short hoods had solid tops which simply had two openings cut into it that were the diameter of the fans, there was no grill to speak of. Baldwin mounted the fans to the bottom of the hood, resulting in the fan ducts (shrouds) penetrating above the hood surface. This style of short hood cover was used on the early DRS locomotives like SP #5203-5227. I've seen a couple of different forms of the shrouds as well. Most were just plain sided tubes, but a couple (like SP #5227) had a stepped outer ring. Also, I've seen some photos of units having "caps" or coverplates mounted an inch or so above the top of the shrouds, while others are bare. Baldwin did away with the shrouded arrangement in the AS-616 series and on a few of the late DRS's of 1950, like the unit I help to maintain: Magma Arizona RR #10. The were replaced by the "flat top" style described next.

 The grills Baldwin used on the later style of flat DB tops are a three part piece made of 2 rectangular panels of 1/16" thick wire mesh in a diagonal pattern that boarder the center panel of welded 1/4" steel rod mesh that formed a walkway. All three panels are the same width and length, and are attached side by side to make a single large panel. The center mesh is the same kind of construction as used on the center walkway over the radiator hatch. The two side grills are the same mesh that is used in the corner vents seen on the short hoods of most DB units.

The side panels of the DB and radiator grills were the same; a special style of perferated plate that punches the steel into 1/4" long slats angled a 45* to make what is in effect a panel of micro-louvers. The neat thin about this grill is that you can see easily through it when veiwing it from below, but when viewing it from above it almost looks like a solid plate! I would kill (well, not really) to get this effect on a model, it's awsome!

I do have a couple of detail shots of the top of the DB grill on MARR#10 with the later style hood, and I'd be happy to share them if you'd like. I'd post them here, but this forum doesn't handle attachments. Details photos of Baldwin MU connections and Commonwealth GSC cast C-C trucks are also available. (those trucks are amazing, and no manufacturer has done a really good job of modeling them so far!)

If there's any other Baldwin questions, please ask!

Matthew Imbrogno
Vollenteer Mechanical Assistant - Arizona Railway Museum

[Mimbrogno]

Actually, the grids were located in the upper half of the short hood compartment, and were cooled by two fans which were the same as those used in the radiator compartment. Later high-hood AS-616s have the DB's mounted above the radiator and use the same fans that it does.

Also, the fan did not pull air downwards to escape out the side grills, it blew it upwards, drawing air in from the sides and out through the roof. (if it's the other way around, the motor connections are backwards!) Knowing the quality of PRR's diesel maintanence, they probably had them backwards most the time which would scorch the crews. And yes, that air is very very hot!

Matthew Imbrogno
Vollenteer Mechanical Assistant - Arizona Railway Museum

[PBenham]

Actually, the grids were located in the upper half of the short hood compartment, and were cooled by two fans which were the same as those used in the radiator compartment. Later high-hood AS-616s have the DB's mounted above the radiator and use the same fans that it does.

Also, the fan did not pull air downwards to escape out the side grills, it blew it upwards, drawing air in from the sides and out through the roof. (if it's the other way around, the motor connections are backwards!) Knowing the quality of PRR's diesel maintanence, they probably had them backwards most the time which would scorch the crews. And yes, that air is very very hot!

Matthew Imbrogno
Vollenteer Mechanical Assistant - Arizona Railway Museum

The effect you refer to about the side grills is visible in some photos of those beasts. And,yes the heat they generated did make the cabs quite warm, so they ran with the cab doors open, which if they got caught by the road foreman- ( time off for at least for 15 days, or a crew shortage, which ever came first!)

[WP 3020]

Mimbrogno, thank you for the detailed replys. I found the shot that led me to believe they had two fans. It is on page 128 in The Southern Pacific in Oregon Pictorial ( the hard to find book with the blue dust cover) by Ed Austin & Tom Dill. It shows two Baldwins that went off the Coos Bay line into the drink. One is on its side (can't see the number) with the top visible and can clearly see two fans under the rectanglular panels as you described. While the other (#5224) is mostly upright and can see a 3/4 view of the two stepped outer rings with some kind of caps (allthough they look to be more than an inch above the ring).
So I gather, the caps were probably added by the SP shops, and if so (like other SP additions) all may not be the same? I could imagin why they would want to have something covering the open fans. One thing I can think of is with all the trees overhanging the tracks out here, the possibility of leavs and fir needles falling in (after being shaken loose by the force of the radiator fans and exaust blast). Then when going down hill, getting sucked up and blown out (possibly getting ignited by the grids on the way) could be a fire danger?
I seem to recall a BLW AS??? dynamic equiped short hood section by itsself being used for load testing at the Amador Central short line.
The reason for the question is that I have 4 Stuart HO models that i want to detail and kitbash into SP units (one being a cabless b unit).
Will have to find a way to see your photos. They soud like the could be very helpfull!

[Anonymous]

The museum in Portola has two AS616's.  I think both former SP via the Oregon Northwestern.  I'd say it's worth the drive to see them for your detail shots.

Smokebox

[WP 3020]

I wnt to Portola in March of 2000, on our way to Winter Rail. I didn't see them there but didn;t realy have enough time to see everything. I did see all three of the Oregon & Northwestern AS616s and the caboose in Hines, OR before they left. I got some pictures but kick myself to this day for not getting shots on top. It was on a weekend and nobody was around to ask, so I didn't take the chance.

[Mimbrogno]

I'm interested to hear how your models come out! I have a small but slowly growing collection of Stewart AS-616s myself, and I want to find a relativly easy method of kitbashing a whole fleet of them to add dynamic brakes. I also wish somebody made Baldwin style MU connections that I could add on in one piece. They are so complicated, it takes forever to make just one with the connection pedestal, three airhoses, two footplates, 5 seperate chains, and the electric plug. It's hard enough to get 3 seperate airhoses to glue onto that tiny pedestal without breaking off or twistng around the wrong way, let alone running the chains around it once you have it in place! Then there are all the imperfections you have to fix up, like the way the handrail mounts are extended out into the stepwell on the ends, you gotta file that down and drill a new hole.

Your right about there being two fans and that SP added the covers above them. They had experianced the same problems you listed about leaves and other debris falling into the DB grids and occasionally catching fire. Because of the location of the DB, placed in it's own well ventalated metal compartment away from any flamable material, a fire wouldn't damage anything more than the grid resistors themselves. And, even if the resistors were damage and the DB was in use, nothing would really happen to the motors or the rest of the electrical equipment. This is because with the damaged grids providing little or no resistance, very little amperage is created by the motors and so there is not much chance of a catastrophic burnout. It was SP's maintanence personel that came up with the modification, but it was Baldwin who finally solved the problem with the second roof grill style.

You also mentioned that the short hood of a scraped SP AS-616 (#5247) is used as a load testing stand. You are infact correct about this, except for the railroad. It is the Sierra Railroad who had this. It's really an elegant system. The short hood with the resistors and the cooling fans were intact, and all they had to do was disconnect the main generator from the motors, and plug it into the test stand. The fans and other auxiliary equipment of the short hood was powered from the resistor grid and the engines generator, so no extra connections or wiring had to be done. http://baldwindiesels.railfan.net/sierra/sp5247.jpg (photo by Jack Neville)

Finally, I'd be very happy to share these photos with you. I think it would b easiest for me to email them, so if I could get you address I'll send them over to you! I also have a few measurements I have taken of MARR #10 of various details that could be helpfull to you and other modelers. I'm working on a scale drawing that will have them all listed, but it's still going to be a little while. I'll be sure to offer that to you when I finish it though!

Matthew Imbrogno
Baldwins are better....Period!!!