K-27 Pulling power

[mudhen]

How many AMS cars, plus a Bachmann caboose should a K-27 be able to pull on a level surface at a realistic speed without stalling ? .
And should using Battery power make any difference except for running time.
Thanks in advance for any and all responses.
      Mudhen 

[armorsmith]

Mudhen,

I can't say for sure on AMS cars, but I have pulled 23 mixed Bachamnn and LGB with mine on our club layout inclusive of a 1.5% grade with no problem.  I have also pulled 26 mixed Aristo cars on flat level, always being about 30% minimum length in a 20' diameter curve if that helps any.

Bob C.

[Jon D. Miller]

Here is a short YouTube video clip of the K-27 with 27 loads behind the tank.

http://www.youtube.com/watch?v=NaQ_K3_t2-c

This particular consist is made up of a few Bachmann 1:20.3 cars. The rest of the consist is scratch built 1:20.3 cars.  The caboose is a modified Bachmann 1:22.5 bobber.  The locomotive had not reached the maximum number of cars it would pull.

The K-27 is coming off a 1% grade and the curve is 10' radius (20' diameter).

Have no idea how many AMS cars the K-27 will pull.  They are not the easiest rolling equipment. 

The K-27 has not been modified in any way.  It is equipped with an RCS PnP.  Kinda puts to rest the early assertions that the locomotive would not pull and the electronics would go up in smoke.

One of the "Enthusiastic Children"


JD

[armorsmith]

Jon,

I cannot totally agree with your comment on AMS not being the easiest to pull.  I don't have enough (3) to make an answer to the question asked, however they roll as smooth as any of my other rolling stock. The secret is keeping the journals properly lubricated.  They are heavier than the Bachmann or LGB rolling stock which will have an affect, but I have no means to quantify that. Either way, the K27 model will pull more cars that the prototype could.

Bob C.

[mudhen]

How many did the prototype pull ? and yes AMS rolling stock is heavier

[NarrowMinded]

As long as you have batteries rated with a high enough mAH and have proper circuit protection your motor wont care where it gets dinner from.

durability of the gears are another subject.
NM

[Kevin Strong]

How many did the prototype pull ? and yes AMS rolling stock is heavier

Not sure what the K-27s were rated at on the D&RGW, but they've got roughly the same tractive effort as the EBT's mid-sized mikados. Those were rated at 18 steel hopper cars with a 2% ruling grade. The D&RGW had steeper grades, so their trains would be shorter--perhaps by as much as half or more on 4% grades. On the other hand, the wood cars weighed less than the hoppers.

Hopefully someone with better D&RGW knowledge will chime in. Google failed me.

Later,

K

[armorsmith]

Kevin, et al,

I have no definitive information, but there is a great video on YouTube of a triple header of K28' on the Cumbres and Toltec. These engines are only 1,000 lb tractive effort more than the K27, so it should be a relatively good guide.

http://www.youtube.com/watch?v=ExA_Oq3LD70

In the latter half of the vid, the train is broken up and one engine leaves with 19 mixed consist and 3 cabeese.  The single loco is on the more level run between Cumbres Pass and Antonito, but again it should make a good guide.  I also read somewhere that a single K27 could handle no more than 8 full tank cars over the pass.

Check in the back issues of Narrow Gauge and Shortline Gazette, there are a number of D&RGW articles over the years.  I can't remember which issue in '76, but one has an article on the stock cars and it has some pretty good pics of consists there.

Good luck!!

Bob C.

[Jon D. Miller]

NM

durability of the gears are another subject.

You obviously have first hand experience with a K-27 and gear durability.  Since there are six K-27s in our club and no one has had a gear problem your insight could be helpfu.

We'd like to take whatever steps necessary to avoid a gear durability problem. Several of the K-27s are now over two years old with many hours so it would be a good idea to keep an eye on these lcocomotives for any duribility issues.

Thanks.


One of the "Enthusiastic Children"

JD

[NarrowMinded]

I'm sorry I didnt mean to imply that there was a gear problem. I know of none.  as long as you don't add any extra weight to your k27 for traction wheel slip should be your safety for not killing the drive gears. others may have opions that are differant.

NM

[rrjTooele]

Dear Bob,

Great video, but I believe the locomotives are K-36s, not K-28s. Great fun. Thank you for sharing the link.

[armorsmith]

rrjTooele,

You are absolutely correct, I should have paid better attention to the numbering. If memory serves, the K27's were in the 450-464 number range, the K28' were in the 470's, the K36's were the 480's and the K37 the 490's.

And I will have to agree that the additional 9,000 lbs of tractive effort afforded the K36 will change the equation on that video. I still have no better info on the K27 pulling power though.

Good catch, and thanks for the correction.

Bob C.

[Charlie Mutschler]

Let's go to the D&RGW employee time tables.  Not much of the D&RGW narrow gauge was flat, but Alamosa - Antonito is close.  The K-27 class is rated at 1,190 tons on this section of the railroad.  Typical D&RGW wooden freight cars have a tare (empty) weight of about 11 - 12 tons, and a capacity loaded of 25 tons.  Cabooses are in the 12 ton range.  Figure empties at 12 tons, loads at 37 tons, caboose at 12 tons.  I haven't added in the adjustment factors, but it's probably safe to say that a K-27 would be pretty well at its limit with 30 loads and a caboose from Alamosa to Antonito - 1,122 tons. 

Antonito to Cumbres, maximum grade 1.42%, K-27 class rated at 600 tons.  That equates to 587 tons (15 loads plus caboose).  The steep side of the pass, the 4% between Chama and Cumbres, is much more restrictive, with the K-27 class rated at 183 tons.  Four loads and a caboose totals 160 tons. 

The model moving 27 cars on a 1% grade seems to be out-performing the prototype.    

I haven't managed to exceed the tractive effort of my K-27 with my relatively short number of cars.  It is one beautiful loco.  I just need to build a combine and I have my tri-weekly Silverton mixed. 

Charlie Mutschler

[armorsmith]

Charlie,

Thank you for posting that most valuable information. I have copied that into my garden railway information data files.

Bob C.