Possibly building a Heavy Mikado

[NKP2-8-4]

LL,

Thanks for the info. I've had the program for a year or two and I found it very helpful while making all of the linkages. They're not seen in the photos because I don't have the hangers done, but they came out spot on. Barring any distractions I'll have her running on air this summer. I hope...

[daz59]

NPK2-8-4,

How big are your pistons and how long is the stroke? what weight are you expecting your loco to be when finished?

Darren

[LivingLegend]

Darren:

I believe the Kreider/Real Trains "Berkshire" has a bore and stroke of 2.75 x 4.25 inches.

LL

[Dave_Johnson]

Just curious, but how much does a set of casting for a Real Trains Berkshire cost these days?

Dave J.

[Rwilliams]

In regards to neglected details on the USRA Mikado, I have been including some nifty items while I rebuild my Mikado into a Southern Pacific MK-9. One of the most visible points of detail on this and many engines is the cylinder jacket sliding inspection doors. I have seen this detail on HO and O scale models but when it comes to 1.6 and 1.5 scale, builders seemt to avoid it like the plague. (If one looks at the Mike model image that Trainman posted, you can see the door on the side of the cylinder jacket) At first it was going to be just a dummy door to look good. Then it turned out to be a operational door complete with slides. I had to make up several bending fixtures and drilling fixtures in the course of this shop adventure. It has been a real learning experience making fixtures to manipulate sheet metal.

I expect to have the test assembly completed this evening and perhaps a photo posted in a day or two. This is the result of locating some original 1920 Alco builder prints that gave all the details. Many of the Alco locomotives built right up to the end of steam with the UP FEF-3 Northerns had the same exact design. I sometimes wonder if Jim had this bit of detail on his original set of drawings.

Robert

[LivingLegend]

Robert:

NKP "Berks" didn't have that feature on the cylinder jackets.

http://www.railpictures.net/viewphoto.p ... 754c6925c3

http://www.railpictures.net/viewphoto.p ... 54c6925c3a

http://www.railpictures.net/viewphoto.p ... 54c6925c3a

http://www.railpictures.net/viewphoto.p ... 54c6925c3a

That sliding door on the jacket was to provide access to a terminal check valve in the center of the cylinder. The check was on an oil line from the lubricator.

EDITED: Added an additional link

LL

[NKP2-8-4]

Yes, the bore and stroke is 2.750 x 4.250. Jim used to say the engine was 1,000 lbs and the tender was 400 lbs. Now it says that the two together are 1,770 lbs dry. Just by how much it weighs at this state of construction I would say the engine is between 1,300 and 1,400 lbs and the tender is in the 400 lb range. The locomotive is only about 5 inches longer than a hudson, but it has MUCH more girth.

Right now the drawings for the engine and tender are $735.50 and the entire casting set is in the $17,000 range. That's engine and tender.

[Rwilliams]

As LL pointed out, there was a lubrication line in the middle of the cylinder that contained a choke and stop valve. The sliding door allowed for easy access as needed to that piece of plumbing.

Some roads used a door of this Alco style. Some roads used other styles and many of Berkshires used no door at all. This is one of the most common designs and used up to the end of steam by Alco.

My question is what type of fasteners were used to hold the slides to the jacket material?

It could have been some large round head machine screws or some small hex bolts. Does anyone know for sure?

My drawings show round holes but no call out for the type of fasteners.

Robert

[LivingLegend]

Robert:

As you said, it could have been large round head machine screws or some small hex bolts.... Depending upon the size specified. It also depends upon the standards of the RR's and/or the builders engineering departments. Or, what just happened to be handy in the RR's repair shops.

Those bolts/screws held the inspection door's frame to the cylinder jacket. Most, if not all of those sliding inspection doors didn't have a fastener holding them closed.... The door used frame friction to hold it closed or open.

I've got copies of both Baldwin's and ALCO's shop standards and specification books. The Baldwin books (3 vols) most likely lists what their specs are. Unfortunately, like most of my other crap, they're boxed up until I can finally move out of where I'm presently at.

By the way.... The NKP Berks were built by Lima not ALCO. The C&O's K4-class 2-8-4's, were quite similar to the NKP 2-8-4's, as both engines were designed by the Van Swearingen's Railroad's Advisory Mechanical Committee. The Kanawha's (the C&O 2-8-4's) were built by both Lima and ALCO.

EDITED

LL

[NKP2-8-4]

NKP's first 15 berks where built by ALCO but did not have the hatches on the cylinders. NKP's final 65 berks were built by Lima. C&O had 70 built by ALCO and only 20 by Lima. I have "been all over" one of each of the engines, NKP Lima and a C&O ALCO, and there are a lot of little differences that could be of concern to model builders. I think that only the C&O berks have that valve and cover.

[MarcelloRupelli]

The Pere Marquette Berkshires were also built by Lima, and I noticed a little oddity. They seem to be the only ones (that I've seen anyway) that have vertical bars in the cow catcher instead of horizontal slats. Pretty inane observation, but it's baffled me.

[LivingLegend]

The NKP Berks built in the early 1930's were built by ALCO. The NKP Berks built in the 1940's were built by Lima.

....I sometimes wonder if Jim had this bit of detail on his original set of drawings.

Robert was refering to the later NKP version modeled by Kreider. That's why I said they were made by Lima.... as Jim's Berk prototype was.

Some other NKP, C&O 2-8-4 differences:

The Kanawha's were:
>Slightly larger/heavier than the NKP.
>The trailing truck had roller bearings, as did it's tender trucks.
>The tender trucks were slightly different w/ larger wheel dia.
>I believe some of the earlier K4's had a Franklin "F2 Precision Screw type" power reverse instead of an Alco power reverse.
>Had the headlight mounted lower. Just abovet the top of the air pump shield.
>Tender had a larger coal capacity.
>Only the C&O engines had Cylinder and steamchest head covers

LL