Building Stage 4 - Part 1

It is frightening to realize that almost a year has past since the last Pearl update. I have been really busy with work and a couple of gauge 1 projects (no, not DOT and DIANA, they have suffered too), so Pearl has progressed slowly. While stage four is not complete I decided to write up what has been done anyway.

Stage four is the stage where all the fittings are installed and the tank, bunkers and cab are added to the locomotive. It actually turns out to be quite a bit of work, and as I chose to add the optional injector and sand boxes I had to scratch my head a bit, as the slim manual was silent on these parts.

Boiler Fittings

The heading picture shows most of the boiler fittings in place. It became very clear to me that the boiler would have to be lifted off the frames at least once more. I will have to take down the motion to fit the crosshead pump (this should be included in stage 2 I think), and I want to clad the boiler anyway. So I did not install the fittings permanently, just screwed them in so that I could ensure the piping was OK.

The regulator body also serves as the steam turret, and has threaded holes to accept the blower valve, the injector steam valve and the whistle valve. The whistle valve goes in the top hole and here I discovered a problem. You can see looking down into the regulator body the actual regulator valve spindle. This has a tapered end that closes the steam line, a bit like a needle valve. If you open the throttle and screw in the whistle valve fully it fouls the throttle spindle and you can't close it. If you close the throttle valve first then you can't screw the whistle valve in. It sticks up as seen here. I am not sure how to tackle this, as it's definitely a design problem. I could cut off some of the base of the whistle valve. Keith Denton, another Pearl builder had the same problem, but found that teflon tape seemed to make a good enough seal.

Brass Dome

The boiler does not have a proper steam dome. Steam is collected by the throttle/turret from a bush on top of the boiler above the firebox. But Maxitrak offer a brass dummy dome that covers the safety valves. This is fitted to the locomotive by a length of 6BA brass all-thread that screws into a bush on the top of the boiler between the two saftey valve bushes. Guess what! Mine was not threaded. So I had to, very carefully, drill out and tap the bush 6BA. The threaded rod then went in OK and the dome was installed.

Footplates

Pearl's footplate is in three sections. The outer two are aluminium castings that bolt on to the sides of the frames. The center section is just a thin steel sheet that rests between the frames and can be lifted to get access to the ashpan. It was clear that, as well as drilling holes in the frames and rear buffer beam for the mounting bolts, I would have to cut out slots in the footplates to clear the boiler mounting brackets and reverse gear.

The plates were offered up to the frames and the slots marked out and then cut out and filed to size. You can also see the hole for the brake stand in one of the footplate castings. They were then offered up again to the frames and the mounting holes marked through on the frames and buffer beam and then drilled. Nothing fancy here, just a regular Black and Decker hand power drill was used.

It was when bolting the footplates on to the frames that I discovered that the front bolt on the right hand footplate came exactly in line with one of the grate supports, and that there was very little room for the two nuts between the ashpan and frame. I ended up filing them both to about half their original thickness, and then it all fitted. These views show the right hand footplate with the larger cutout for the reverser stand, the left hand footplate, with the brake stand fitted, and the brake linkage under the footplate.

Blower

The blower is a simple piece of copper tubing that runs from the blower valve along the boiler to the smokebox and then curves up parallel to the blast pipe inside the smokebox.

Saddle Tank

The saddle tank is an aluminium casting that sits on top of the boiler and is held down by a screw through the bottom into a bushing on the boiler, and two brackets in the front, that are screwed onto the smokebox. Well, the bush was tapped OK this time, but the mounting hole in the bottom of the tank was drilled in the wrong place! So I drilled out a new one and will have to plug the wrong one. As you can see the tank fits very snugly between the dome and the stack. You can also see the blower line entering the smokebox.

Injector

I purchased the optional injector. The istruction manual has a sketch showing where it goes and how to plumb it, but nothing else. You are very much on your own here. It was pretty clear to see that I would have to drill the right side footplate for the steam and feed lines, and also for the water valve. The steam line goes from the valve on the turret to the injector, and the feed line goes from the injector to the check valve on the backhead. You can see the holes in the footplate for the pipes and the water valve, and this view shows the plumbing and injector under the footplate. The injector is just held in place by the pipes, as is the water valve. I don't like this so I'm going to make a bracket to firmly mount the water valve. This view of the footplate shows the plumbing to the injector. It also introduces the bunkers, seen placed on the two side footplates.

Bunkers

If it appears that the bunkers tilt out a little, they do! I was struck by this and wondered if that was how they should be. But it didn't look right, and it would also make it very difficult to fit the cab front, which is attached to the insides of the bunkers. More on this in a minute.

The bunkers are made up of aluminium castings with a sheet steel back. The first job was to drill the backs and castings to take the self tapping screws that fix them together. Then they were positioned on the footplate castings and drilled through for the mounting holes. The bunker on the right has the hand feed-pump in it, so the hole patern for the base of the pump wsa used so I could bolt the pump straight through the bunker bottom and footplate.

Now back to the tilt. Looking closely you can see a definite outward list! it appears that ths is due the "draw" on the castings. I could have filed the bottoms square, but decided I'd rather take them to work and borrow a mill and machine them square, which is what I did. They now sit nice and square on the footplates.

The picture below shows Pearl at this point. It doesn't have the bunkers fitted in this view, although they are ready to screw on. I'm working on the cab now and should have some more pictures soon. But then, you've heard that before!

Go to Finishing Stage 4