Does anyone have a list of the K-27 specifications, such as all the usual info on a builders card. I am primarily looking for the manufacturer’s stated top speed.
Thanks,
Bob C.
Bob,
I don’t think manufacturers listed top speed in their specs as that had a lot to do with track condition, tonnage being hauled, grades, traffic density, rules and many other factors.
The listed roster for the K-27 class is as follows:
17x22 cylinders
40" drivers
200# boiler pressure
27,000 tractive effort
136,650 weight
Originally these engines were built (1903) as Vauclain Compounds with 13 + 17 x 22 cylinders and slope backed tenders. They were simpled in 1907-1909 and later given rectangular tenders.
Richard,
I have seen some listings on standard gauge locos giving top speed, but I will admit it was usually on mainline engines for passenger or fast freight. I have the B’mann K-27 without sound. I have been watching videos on Youtube of the K in action and by cadence of the side rods and counting revolutions I believe the fastest I have seen on the videos is about 20 miles per hour.
What started me on this journey was reading a past thread on the B’mann and all the hullabloo about the gearing. So based on dirver diameter and a guess that the Pittman motor is the largerst 9000 series motor the claim that the gear ratio should have been 28:1 (or there about) is accurate. The 14.5:1 gives a top speed of near 45 miles per hour and I believe that to be way too high for that locomotive.
All that being said, I am not unhappy with the performance, just doing my own investigation. With mine running at about scale 20 MPH I am at 14 volts +/- and about 1.25 amp pulling 19 Bachmann Big Hauler cars with steel wheels lubricated with white lithium grease. This test was done on our club layout main loop which is flat. As soon as we get the second loop finished I will be able to test it on a 1.5% grade.
Thanks for your response. I had most of that data, but not that they were originally supplied with slope back tenders. I have never seen a picture of one like that.
Bob C.
I will tell you, 19-20 cars on level track is no problem.
You fall off the edge of the current curve on a 4% grade.
At 14.5:1, the current jumps, depending on type of rail (mine is old aluminum) and curvature, I have measured over 4 amps.
My B-man K has been parked.
If I am going to use one, it will be my Magnus.
Unless of course someone comes out with new gearing.
BTW, with loads like you are running, make certain the gears are lubed and in good condition.
The load on those gears with a 9000 series for torque and 14.5:1 is going to create some interesting situations down the road.
Deleted as not appropriate
Fred, Fred, Fred.
Fred Mills said:Hehe! Whatever it was Fred I'm sincerely sorry I missed it! ;)
Deleted as not appropriate
Knowing the good Padre, it would have been insightful and introspective.
Too bad a certain “consultant” was neither…
As a general “rule of thumb,” top speed for a steam locomotive was accepted to be approximately equal to the driver diameter in inches. While a “rule of thumb,” it was a rule that anecdotal evidence has shown to be a bit underestimated. For starters, the locomotive that first broke the 100mph barrier did so without the benefit of 100" drivers. There’s a story of one of the EBT’s locomotives pulling an ailing company official to Mt. Union in excess of 60 mph between Orbisonia and Mt. Union. The loco on the point had 48" drivers. Even in the best of years on the EBT, that had to be some kind of white-knuckle ride.
Later,
K
On the backhead of the 464 is a sign that instructs the engineer to limit the top speed to 30 MPH Such a sign is rare in any locomotive. I have no idea when management placed that sign in the locomotive but such a sign is rather good evidence that engineers were routinely operating said locomotive far in excess of that speed and management wanted to reduce this practice.
Most locomotives were capable of reaching top speeds on a flat far in excess of the speed they routinely ran at and there are a variety of stories of clocking a locomotive at speeds that likely ran shivers down those riding the train. I recently was the engineer on a steam locomotive and was clocked at 68MPH. The throttle was not open much at the time so the locomotive clearly was capable of far greater speeds. I have been in the cab of a K27 at 15MPH and the throttle at the time was only opened a little. On the flats the 464 is clearly capable of far greater speeds.
For the K27 there are numerous reports of speeds in the 45 mph range. I am not sure I would have wanted to be on a train on those track conditions at that speed.
Stan Ames
30 MPH was the high end for the K’s.
An old video of mine shows one stepping out near Tiffany, Co. The narrator states it was doing close to 30 MPH, which was its maximum. Anything greater was dangerously close to de-railment and or the loco coming apart.
These were not high speed locos. Their narrow stance on the drivers (3 feet), rough track, relatively tight turns and other factors contribute to the top mph.
There he is, defending the indefensible once again.
Gentlemen,
Thanks for all the great input. It appears that there are several opinions as to the top speed as designed by ALCO. There are also some very good logics stated as to what would appear to be a ‘safe’ top speed. All of that being said, and after reading a past post on the subject, I will offer my opinion.
First, TOC I did not see any one defending anything, nor did I see anyone attacking anyone else.
Second, as for the gear ratios on the K-27, depending on which point of view you chose based on the above commentary it could/should be any of a number of ratios. As I understand it, it is provide from the factory with a 14.5:1 ratio gear box. I have seen several posts referring to a 9000 series Pittman motor. There are about 5 or 6 (don’t remember exactly) motors in that series. If for the point of this discussion I chose the motor with the highest torque ability, that motor maxes out at 5010 RPM. Doing the math from there with a 40" driver, the max speed is somewhere about 45MPH. That would fit close to the ‘driver diameter equals top speed’ rule of thumb, making the as supplied ratio close to correct if one wants to go that fast. I have run mine for a short distance down the 90 ft straight at my club layout and don’t want to do it again. Most of the video I have seen of the K’s seem to have them running somewhere about 20-25 ish. If one goes to the 28:1 ratio as has been suggested by any number of people on this and other forums, then your top speed would be about 21 MPH, slightly slower than the videos. If one choses to go the 30 MPH route for a top speed, then another ration must be calculated.
I didn’t have any intention to touch off such a powder keg. I also got the impression from that past post the Mr. Stan Ames and Bachmann are somewhat synonymous. That being said, I would be interested to know, if the speed restriction Mr. Ames alluded to above was known before production of the K-27, why did he gear the engine that high? I might have been more inclined to go in the 20:1 range making both ends of the spectrum better.
In my post above I mention a run on my club layout using all my personal equipment. My first run, ‘right out of the box’ was at a club road show. We took one of our members USA Big Boy off the track, put the K on and coupled up to 27 Aristo cars. I did not have the luxury of metering at the show, but the locomotive performed well. TOC I will take your advice and put on my yearly maintenance to check the grease in the gear box. Maybe I will look into some ‘Royal Purple’ stuff they advertise on Power Block TV. 
Thanks again for the great input. That is what makes this one of the best forums on the net.
Bob C
Wasn’t you “defending the indefensible”.
I know which motor it is.
I know what the gear ratio was supposed to be.
I know what it is, in fact, I do believe I was the first to actually count the turns, but I could be mistaken.
BTAIM, try it on a grade and see what your current is.
Some…people…have tried to say 14.5 was a design consideration.
Hog.
Wash.
Dynamic augment at speed with the outside frame can be interesting, as rail damage can be the least of your worries.
Rule of thumb:
Unless I address you directly, be advised, I am not referring to you.
Cope with it…oh, did I just say that?
TOC,
Please accept my apology, I mis-interpreted the ‘he’ in your “There he is, defending the indefensible once again.”.
I am neither condemning nor defending Bachmann’s choice of gear ratios, only attempting to understand their choice relative to the prototype. Nor am I disagreeing with any of your prior statements. I have no doubt that yourself, Barry and many others have been at this large scale hobby far longer than I have.
If you wouldn’t mind, please inform the ignorant what ‘BTAIM’ is?
I Cope with things very well, thanks.
Bob C.
Be That As It May.
BTAIM.
You are not, someone else still is.
I know, unfortunately, what is inside of these.
I know what was recommended and why.
I know (simply because I was told) what actually happened.
And, I don’t care.
Not until they fix it and straighten out what they did, I don’t care.
Curmudgeon said:Dear Curmee, what you 'know', seems to be your problem. You cannot prove anything, except that you can count the turns;-)))... The maths has been done before and everyone with half a brain can see that the 9000 series motors require higher gearing than the 8000 series. Bob produced sensible arguments, others provide excellent test results, but you just keep dissipating heat in half-grammatical sentences... Best wishes from Tokyo, Zubi
I know what the gear ratio was supposed to be. I know what it is, in fact, I do believe I was the first to actually count the turns, but I could be mistaken.
Sorry Zubi.
You just don’t get it do you?
Theory is all very well. What we would like to see from you is factual reporting based on actual experience of using the K-27 on a garden RR with variable grades. Something, by your own admission, you have not actually done.
I know for a fact what happens on grades with the K-27.
The loco bogs down and speeds up depending on the load.
A situation that does not happen with the Mallet, because it has a sensible gear ratio.
Oh, Oh… a duel that can’t be won, is starting up…stand back…watch out for flyng words of all sorts…This duel has already been watched numerous times by several other challengers taking on more than they could handle…more feelings have been hurt, and wounds that never heal have been inflicted.
I suggest both parties step back and realize what the battle accomplished in the past…and then Bobby stepped in.
I think most of us accept the facts that have come out on this topic. No need rehashing them all over…please.