Chris's Holly Pumping Engine Build

[crueby]

Thanks for stopping by Mcgyver! 




Today I got the rest of the railing bases made, can get started on the pump plunger tops now, after I finish some rc sub parts...

[crueby]

So back on the pump plungers today, and have a very dull photo, starting to size up the stock for the plunger top plates. These will have a hole bored in the center to fit the top of the plunger, a hole in each corner for the rods that go up to the crosshead to move the plungers, and some ribbing milled in between all the holes.

[cnr6400]

 

[Craig DeShong]

This model is absolutely impressive in its current state; can’t imagine the show-stopper it will be when you finish it.
  

[crueby]

This model is absolutely impressive in its current state; can’t imagine the show-stopper it will be when you finish it.
 

I shifted the model so far on the bench, its already getting to be a heavy beast! Once done, going to need the elves to call in some friends to move it.
 

[crueby]

After getting the blanks for the plunger top caps trimmed to size, the center holes were bored on the lathe then the corner holes drilled on the mill:

Test fit on one of the plungers

Then started in milling the top/bottom faces for the recess pattern, first the sides at 90 degrees

then angled the vise for the diagonals - took two setups, since the blocks are not square, so the lines are at 43 degrees

Ready to loctite and cross pin the blocks onto the plungers - still need to round the corners on the sander.

I also got the two platforms cut out of sheet aluminum, these platforms will sit between the pumps on top of the intake pipes. They gave acess to the pumps and the seals around the tops of them. There will also be stairs leading up to the platforms. The bottoms of the panels are supported by angle stock riveted in place with some 1mm brass rivets. Slow going to cut the angle stock so it can be folded for the corners, but its faster to handle one piece than dealing with four separate short pieces. Now to make 7 more of those and the longer cross pieces that go across the middle


Closer view, also shows the rivet squeezer in the background

[Firebird]

Hi Chris

I'm still following along 

Can you show a little more of the rivet squeezer please.

Cheers

Rich

[crueby]

Hi Chris

I'm still following along 

Can you show a little more of the rivet squeezer please.

Cheers

Rich

Sure thing Rich, very handy tool. I built mine after seeing one in another thread here several years ago. This one has an added extension option for getting into tight spaces. It will appear in my column in Live Steam sometime in the next couple years, not sure when. In the meantime, I've attached the plan sheet for it. The dimensions on the U shaped head can be changed to suit your bar stock, but the spacing on the holes for the moving parts should be done as is, they take some care to lay out. The top threaded anvil can be run in and out to suit the thickness of the material. It works with rivets that have one end formed already, and it squeezes down and forms the other end - cut the shank of the rivets to stick out a diameter or so. Works great on brass and copper rivets, never tried it on annealed steel but should work on small ones okay. Very handy device, easy to make. Enjoy!
Chris

[cnr6400]

 

Liked the plunger top pics! Must be massive things in the real engines. 

[crueby]

Liked the plunger top pics! Must be massive things in the real engines. 

The real plungers themselves are 37-1/2" in diameter and nearly 7 feet long (stroke is 66 inches), the top caps are over 14" thick and almost 4 feet across! Not solid blocks, all are hollow castings, but quite thick. Its amazing to see all the massive pieces on these engines, then the much more modest sizes on the Corliss valve levers/linkages.

[crueby]

Once the first angle bar was made to check the distances between cuts, the rest were pretty quick to mark and cut, remembering that half of them need to be mirrored for the opposite corners.

They were all drilled and riveted like the first one. Here is one of the platforms set in place on the intake pipes to show where it will go. One of those parts that is not very visible, but still worth putting in. The narrow end facing the camera will get a stairway from the base plate up to the platform.

And now the really 'fun' part - bending up the railing and installing the posts into the platform. Not too hard, but I have to remember to run the railings onto the posts before bending (had to heat and straighten in one spot where I forgot, the post cap wont go around the tight bends  ).  Assembling all the posts, with bottom caps, into the holes took some fussing, cussing, and retries!

One railing on, three to go (two platforms with two railings each)...  Good practice for the upper platforms where they will show more, at least those dont have all the jogs in and out, just gentle arcs at the ends.

[cnr6400]

 

Thanks for the plunger and plunger top cap info Chris! I have a lot of respect for the designers and builders of the full size engine all those years ago. Great progress on your engine! 

[Kim]

Lots of little fiddly work on those , Chris, but it's all those details that make the model stand out! 
Kim

[crueby]

Thanks guys, this afternoon got the second railing on the first platform. Had to trim a couple of corners and edges to get the platform to fit down between the pump chambers. Plenty of room down in place, but it wouldn't quite get there with the railings on. Just minor trimming, sort of like getting a  piece of furniture around that last corner of the hallway.

[crueby]

Catching up on the railings - here is a picture of one platform with the railings, one without (one of its railings is on now, and the first one has had a coat of paint since this was taken)


Last night I was thinking over how to make the jig for the stairs, when it hit me - I have a 3D printer now!      So, printed up the four stairs for leading up to the platforms:

Also designed up the freestanding ladder that was used in several places at the pump station, going to print a couple of them. And printed up the elbows and tees for the air lines that will go between the holes near the top in the force chambers above the check valves. All six of the chambers were connected by this piping to balance the pressures and help damp the movements. I found the patent for the design of these Holly engines, and it calls out this setup. I had originally thought that they pumped in pressurized air to these chambers, but not so, they just had small valves top and bottom to check the level of the water and to drain some out/add air at the top if needed.


These parts need a spritz of paint and the straight pipe sections between the fittings. I had seen in the plans that there was an air pump, and had assumed it was to pump air into the force chambers. More digging in the plans and photos I took, and I finally figured out where the pump was - it was on that little half-circle at the side of the LP pump base plate. The 'air pump' was actually an air-pressure-powered water pump! They took the oscillating pressure from the force chambers, and ran a small air pipe down to a pump on the floor that was used to scavange up water from the floor around the engine, water that may have leaked from pipes, from the pump seals, and condensation from the air on cold water pipes. The air pump was a large diameter piston with just a few inches of movement, and had a chamber with check valves underneath, with openings around the edge. It was a floor-mounted sump pump essentially. It turns out that these pumps were never installed on the Ward Station pump engines, since they had floor drains that could run off to the local storm sewer lines, so no need for the pumps. This explains why they showed the parts of the pump in the drawings, but there was no evidence of them (no pipes/fittings leading to them from the force chambers) other than the provision for the mounting bolts on the edge of the LP pump base plate - they were part of the standard pump engine but not installed on the ones at this location. Fun detective work! I had spent a lot of time looking in the photos for the air pumps, finally checked the mounting bolt pattern and dimensions on the plans and spotted that they fit the bolt holes in that base plate, then it all clicked - the plans are of each individual parts in this giant engine, there is no general-assembly drawing of the entire thing, just subassembly drawings for things like the Corliss valving.