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Monday, 28 May 2012

Draw-bar Recovery (3)

My previous article on this subject finished the construction of the replacement rear draw-bar cover.

After a good few coats of paint and trial fittings, it's now in place, complete and ready to be trodden on.

Ok, so this is the before...
...but this is the after!
I just had to be the first one to get my footprints on the new paintwork!

(Apologies for some recolouring to remove an intense blue-hue caused by the blue tarpaulin roof structure).

Sunday, 27 May 2012

WWII Blackout

Midsomer Norton Station has been steadily amassing exhibits of World War II artefacts and re-creations in addition to its many historical attractions; Sentinel 7109 couldn't wait to get involved.
A rare unobscured view of 7109's near side
In the above view of 7109, light is no longer showing from inside the cab; the blue hue has been hidden from view.
What? No boiler (again)?
The boiler has been made invisible and, in the photo below, trees are now reflected in the cab side black-out panels.
Could do with a good clean up too!
It's taken quite a while to produce these black-out panels; they've taken up a lot of room in my garage and are the main reason for reduced 'blog output of late. Normal service should be resumed shortly!

Wednesday, 16 May 2012

Straining the Rubbish

An earlier article has described Sentinel 7109's boiler feed pumps including the cab-mounted one on the right hand side.
Original Cab-mounted Boiler Feed Pump
The pump has to draw water from the water tank via pipework and a coarse strainer situated in a right-angled fitting and isolating valve housing just in front of the cab.
Strainer and Valve Housing by Water Tank
The picture below was taken just after Sentinel 7109 arrived at Midsomer Norton Station in December 2004. It shows how scale and rubbish accumulate at the bottom of the tank. The pipe at the bottom of the picture is the take-off for the cab feed pump. It does not suck directly from the tank bottom and so not too much detritus should be drawn. However, to be safe rather than sorry, the strainer is included. (Another in-line strainer may also be added at the pump inlet).
Bottom of the Water Tank
Since the above picture was taken, much of the scale and rubbish have been removed using a domestic vacuum cleaner (honest!) with a long hose to reach in from the top. Some chemical de-scaling may also be necessary in the future depending on how 7109 reacts to water treatment. An awful lot of Kilrock-K is needed for this type of kettle!
Coarse Strainer Housing
The strainer housing is shown above. When it was first opened, a rather distorted, vaguely cylindrical-shaped, perforated, oxidised, copper thing came out. On trying to reform it into shape, it was obviously going to break and eventually it did.

However, since it was already broken, there was no harm in at least trying to fix it.
I heated the parts to red heat and quenched them in cold water to anneal (soften) them. Then I did the reshaping using a rubber mallet, a 4lb hammer as behind support and a broom handle about the right internal diameter.

I then silver soldered the pieces together as in the picture below.
Repaired Coarse Water Strainer
Hopefully I haven't blocked too many of the strainer holes and it may work better in some orientations than others. However, I think we have a strainer capable of going back into service again!

Monday, 7 May 2012

Wrong Trousers Appeal?

For impact's sake, I couldn't resist a little mischievous colour manipulation for this posting. The item pictured below is normally found the other way up and in red but I thought it had a certain Wallace & Gromit appeal as shown.
Eat your heart out Wallace!
What about a new pair of hot-pants?
More seriously, I'm appealing to owners of Sentinel locos with the 100HP boiler to join the numbers requiring a new Funnel Base.

Sentinel 7109 uses a pair of these double chimney units mounted above the boiler inside an outer shield. One of 7109's Funnel Bases is in a poor state and needs renewal; the other has seen better days but will be serviceable for a few years yet (but it's not much use on its own!).

Twin double chimneys and outer shields
The 100HP locos with the '25% larger than standard' boilers have a single double chimney unit of this type. (Sentinel waggons have a rather different type with a longer 'bell-bottomed' profile).

Richard Nixon, Sentinel Drivers' Club Drawings' Officer, is 'in the throes of' arranging for patterns to be made for new Funnel Bases to be cast. The more required, the wider the spread of the pattern costs even if rather earlier than planned.

So, if you are reaching the stage where your funnel base will soon need replacing, please contact Richard whose Email address can be found by clicking here.

To check if this is the type that you have, a drawing of the funnel base is shown below although a better resolution version may be required from Richard. (Click the drawing to enlarge it).

Funnel Base Drawing
(Drawing courtesy of the Sentinel Drivers' Club)
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