Hooked

As Sentinel 7109 progresses through its new working life, I run into many little irritating operational problems that can be solved quite easily. Filling the water tank is one.

We use a 6-wheeled tanker wagon as reservoir. It's simple to fill the tanker slowly from a domestic supply tap when there is plenty of time. For rapid watering during operations, we use an impeller pump at the tanker to pump along sections of flaccid hose linked by claw couplings to Joyce's tank.

The trouble with a flaccid hose is that it's flaccid. It flaps around merrily in the top of Joyce's tank while filling and is partially blocked by the weight of the tank lid sitting on the hose to prevent it from jet-propelling itself out.

I made a more resilient hose extension to overcome the problem.

Not-so-flaccid hose extension

It neatly hooks over the tank filler rim and doesn't get squashed by the lid.

Simple but effective

Hopefully, we also won't get quite so wet when the tank overflows (which never happens, of course!).

Frost Damage February 2019.

Sentinel 7109 was surprised by a sudden frost in early February 2019 and suffered some damage to the pipework feeding the cab's boiler feed pump.

In June 2013, I wrote extensively about the construction of an elaborate plug valve with a hidden secret. It was originally fitted in 1928 so was a historical gem.

Plug valve in water feed line.

However, after the frost, I found it looking rather sorry for itself.

Split top bit

On taking it apart, I realised that it was beyond repair as the internal plug itself had split into two pieces.

Split plug

It's a shame to lose an original part in this way but it was also an opportunity. I suspect the 1928 construction had perhaps been done in a hurry; Joyce was a prototype after all. Where the pipe came from the tank to the 'T' piece, a strainer was hidden across the top of the 'T'. The valve was downstream of the strainer.
There was a disadvantage with this in that to clear the strainer by removing the plug from the end of the 'T', the tank had to be emptied to avoid a personal irrigation. So the valve should have been upstream of the strainer!

I've resorted to modern parts to rebuild the valve and strainer with the disadvantage removed.

Ball valve and 'Y' strainer

The pressure on the ball valve is only the head of the water in the tank, about 6 feet max., so there are minimal requirements for it. The 'Y' strainer is now downstream of the valve and the strainer's cap (pointing downwards) can also be used to drain the water pipe for frost precautions as well as cleaning the strainer. With any luck, the new strainer will be less restrictive than the old one so the water pump should be more efficient.

I'll tidy up the appearance in due course [as below].

With a lick of paint...

...And some frost protection where the pipe can't be drained

Front LHS Water Filter Valve Repair

It was 2012 when I last wrote about Sentinel 7109's water tank filter valves. There I described how they worked and could be used to drain water pipes to avoid frost damage.

Early in 2016 just after 7109 had begun her new steaming career, there was a frost forecast so I followed the procedure and removed the drain plugs to empty the pipes.

That evening I received an urgent phone call saying that water was pouring out of the LHS of the water tank. This was not good news 25 miles away on a dark cold night.

Investigation showed that the front LHS valve was not only emptying the pipes but the entire tank!

I consulted Justin Goold who informed me that although these valves had a phosphor bronze valve spindle, they had a cast iron valve seat. The seat tended to corrode over time leaving the valve unable to close properly.

The solution was to machine out the valve seat and replace it with a brass insert which would not corrode and hence be more reliable for the future.

I couldn't do this myself and it needed to be done quickly between steamings. John Goold did the honours and it now works as it should.

New brass valve seat insert

Many thanks to John and Justin. What would I do without you!

Hidden Secret

Sometimes the simplest looking items turn out to be more complicated than expected. The off-side water feed valve is one of these.

WS BFP Water Feed Valve

And the same but closer (restored)

It's a 'Plug' valve with a tapered plug and rectangular slot. The plug is held down into the valve body by a screw-down gland plate. These are fairly simple ideas; however, the valve body and its spindle have a hidden secret.

The 'Plug' (Spindle)

Valve body

On the surface, it's easy to see the rectangular slot in the plug which either allows water through or blocks the flow depending on which way it is set.

There is a slot around the top of the plug taper with a pair of holes diametrically opposite each other. So what are they for?

On the top of the spindle is also a hex headed screw. So what's that for?

Hex head screw

Initially, the hex head was well jammed-in with old paint and immovable. With a split-pin hole across the hex head, it looked as if it might have had a purpose at one time. I dug the paint out and managed to free the screw and its purpose began to become clear.

On removing the hex head screw, I could see another screw inside the spindle hole so I removed that too.

Hex head and internal screws

At the bottom of the hole in the spindle is a chamber with the pair of holes leading off to the slot around the top of the plug.

The internal screw is more subtle than I'd initially imagined.

Internal 'screw'

In fact, it is hollow and contains a ball bearing retained by a loop of wire. With a pair of slots at the lower end, the ball acts as a non-return valve.

With the screw in place at the bottom of the spindle hole, grease is loaded into the hole above (best done with a grease gun). The hex head screw is then screwed in to push the grease through the valve and out through the holes to the slot around the top of the plug.

The valve body design works with the plug to distribute grease to all the places it is needed.

Inside the valve body

Looking down into the body, there is a cut-out in the wall which coincides with the slot around the top of the plug. There is also another cut-out at the bottom of the body (the plug-hole?). There are also identical cut-outs opposite the ones visible in the photo. The cut-outs also coincide with four slots down the plug surface.

One of the four plug slots - Note the dark patches at each end of the slot
which match the top and bottom body cut-outs

The grease can thus be forced down into the slot around the plug, through the upper body cut-out, down the slots and finally into the lower cut-outs and the bottom of the valve body. The whole valve can thus be greased in situ whilst doing its job immersed in water. Clever!

A few notes:

Grease can be forced in with the valve spindle in any position. The cut-outs will prevent grease ending up in the water space.

The valve is open when the top looks like this:

Valve Open

The valve is closed when the top looks like this:

Valve Closed

The slot through the plug is in line with the 'pips' on top of the spindle.

Slot lines up with the 'pips'

Not a lot of people know all that!

Water Supply (1)

One item that was missing when Sentinel 7109 arrived at Midsomer Norton Station in 2004 was a section of water feed pipework running around the front of the leading engine supplying water to its boiler feed pump.

I decided that the simplest way for me to make this was using mild steel pipe with malleable iron fittings and here it is.

Water feed pipe to front engine's Feed Pump

I concluded that the best method of joining the new pipe to the old and to the pump itself was by using parts from a union fitting. Nominal 1 inch inside diameter unions made by Crane use a 1.5 inch BSP thread for the union join - the same as at either end. Thus I was able to achieve joints without any air pocket. Other methods such as off-the-shelf reducer fittings have a bulge where you don't want it!

Water feed pipe across from left to right

For water systems under pressure, an air pocket is not an issue but where water has to be sucked by the pump from the tank, the air pocket will prevent the suction taking place.

Water feed pipe past the rear engine from
the water tank filter valves

Note: Crane and (I think) Georg Fischer unions use 1.5" BSP joint threads for 1" pipe; others I bought via the internet do not. Beware!

Domestic Help

After pressure washing the water tank walls to remove scale and rust debris, I managed to finally dry the inside of the tank by dangling a domestic vacuum cleaner in the tank so that it inhaled air from the tube outside and exhaled it down inside the tank. Sorry no photo but I confess I did feel just a little smug at thinking up that idea!

Some remaining debris could now be seen so I repeated the earlier vacuum cleaner treatment complete with long extension handle.

Domesticity reigns

Right down there; it's about eight feet to the bottom.

Long range sucker

Now the tank is ready for use.

Built like a Tank

I mentioned needing to de-scale Sentinel 7109's water tank in an earlier article.

The water tank is the large four-inch thick cast iron object between the cab/boiler and engines.

Central 600 gallon water tank

In 2004 just after 7109 arrived at Midsomer Norton Station, I poked my camera into the tank to see what it would be like.

Bottom of Tank in 2004 (Loco front to the right)

I used a domestic vacuum cleaner with a very long tube to lift most of the scale and rust deposits from the bottom leaving it a lot clearer but with plenty of scale still sticking to the tank walls.

After considering a colossal amount of Kilrock-K, I resolved that the simplest and cheapest way to remove the loose scale was to use a pressure washer. The results are pictured below (taken some time after the spray should have subsided).

Lots cleaner

Despite having waited for the spray to subside, the next picture shows a strange, persistent and welcome phenomenon.

Where has all that steam come from?
It really wouldn't go away.

Perhaps Joyce is starting to realise she's coming back to life and making her own contribution?

It could be a sneer at the photographer from above!

Off subject but I noticed an unexpected reflection
before the tank dried out!

Cleaning out the tank has been holding me back from fitting the water valves to the left hand side.