7202 News

7202 line drawing

18 December 2016

Over the last 2 years work has mainly been concentrated on the boiler, with preparing for further examinations, this has included removing the back & front 3 rows of crown stays as well as 10% sample of other crown stays for inspection and removal of part of the throatplate. Following these inspections it has been decided that all of the crown stays will be replaced and the bottom section of the throatplate. We have obtained a new tube-plate, but we will not fit this until we have finished going in and out of the boiler barrel, it is far easier to go in the front rather than in the top each time! We have removed a percentage of the crown stays, these will be replaced with new ones before removing any more, this involves ordering several special taps and having the stays made so is not just a days work!

Here are a few pictures inside the boiler showing what it is like.

This picture is looking over the top of the firebox, the pipe on the left is the main steam pipe. On the left and right can be seen the veritcal crown stays, in the middle and front these have been removed ready for replacement.

Reulator pipe & stays

This is a side view of the main steam pipe, the pipe heading out to the left, towards the rear of the engine, is where the regulator rod passes down from the cab to the regulator in the smokebox.

Regulator pipes

At the top of the picture is the end of a pipe feeding one of the fittings mounted on the back of the boiler, collecting steam from the highest point in the boiler, the large item is one of two pipes collecting steam to take to the regulator.

Steam collectors

Visible in this picture is one of the longitudinal stays from the back head, this one only goes as far as this bracket on the back of the barrel.

longitudinal stay bracket

This is another longitudinal stay, this one goes to the top corner of the throatplate, on the outside there is a large nut. Also visible are some of the holes where crown stays have been removed.

longitudinal stay

The smokebox has now been placed on the frames to keep it inside in the dry and allow a few other things to be done such as hand-rails. The nw chimney has been placed on the smokebox as well, it hasn't yet been lined up, this iwll only be done when the boiler and smokebox are fully re-united.

7202 with smokebox

Other tasks that have been ongoing include completing the axlebox lubrication pipes, refurbishment of the cylinder cock rods, cab floor support work, steam lance cock, whistle linkage and some pipework.

31st December 2014

The glass for the cab windows has been fitted using the original method of a felt packing between the glass and the frames, the handles have been fitted and the windows fitted in their holes out of the way for now, although when we lift the roof off they may well have to come of again. Both of the connection rods are now fitted in place along with the relevant crank pin nuts and securing pins. A new rod for the vacuum pump has been machined, this is awaiting grinding before fitting. A start has been made on the pipework for the injectors and vacuum system, this has included making various pipe clamps to replace ones that are either missing or rotten.

The boiler has been examined, whilst we have had this done previously we have since changed insurance companies and the technology available has improved, this has found cracks in the back-head, similar to those found in other engines. Where the plates on the side and front are wasted these will need to have sections cut off and new plates welded in. The front tubeplate was known to need repair, it has now been decided to replace it so it and the smokebox bave been removed.

Boiler barrel Tubeplate

In the barrel are the 6 longitudinal stays, these help support the tubeplate and backhead, preventing the pressure in the boiler deforming them. Also visible are the blower pipe and the larger vacuum ejector pipe, the later looks as though it has been leaking judging by the amount of scale in the pipe so requires further investigation, although it looks as though it has already been repaired once as there is a join about 12" in to the barrel.

17th December 2011

All of the eccentric straps have been fitted along with the eccentric rods, these have temporary pins, a start has been made on roughing out new pins but this job will be done between other jobs and when it is warmer as standing next to a machine in this cold weather is not always nice!

One of the connecting rods has been fitted, the second has had the big end bearing white-metalled and needs machining and fitting, then the thrust face done.

Work on the cylinder cladding is progressing with the front part of the engine starting to look complete.

There have been many other small task done this year, including final riveting on the cab, start made on boiler cladding frame work, brackets to stop spring adjusters moving and many other small tasks.

5th May 2011

The eccentric straps have now all been white-metalled, machined, cleaned and painted ready for fitting. The eccentric rods have also been cleaned and painted in preparation to fit with the straps, these will be fitted with temporary pins while new ones are made.

The second of the balance pipes has been fabricated, both are now being painted before fitting to the engine, they will need removing when the tanks are removed, but at least they will be off the floor and out of the way!

11th January 2011

The reverser has been fitted in position, although the quadrant will have to be removed when the tanks come off to allow fitting of the boiler. As part of the reverser catch mechanism was "borrowed" to replace a broken part on one of the other engines a drawing has been made to create the new parts, these will then need hardening and tempering.

All of the coupling rods are now fitted so we have a 2-8-2t again. The little end bearings have been attended to, we just need to sort out the big end bearings and these rods can then be fitted as well. As the cross-head cotter was gassed off we are having to modify another one to fit, this is a slow task as the part is being machined off site and regularly coming back to site to be checked to ensure we do not take to much off.

After several experiments creating a tool to form the end of oil pipes we have now started to create the missing oil pipes to the axle boxes. Tools to create the pipe ends, also required but not shown is gas. The process is quite simple, heat up the pipe ensuring that the portion closest to the clamp is really hot, then hit the former, stopping when the part has gone cold, repeat until the end is fully formed.

Tools to form endPipe endOil pipesphotos Richard Needham

We have had new handles cast for the front cab windows, these need cleaning up and fitting to the windows. The windows are in the last stages of fitting to the cab, although we have not yet made a template to order the glass.

Window handlephotos Richard Needham

14th March 2010

Work has continued with fitting the reverser quadrant, the holes in the side of the tank were found to be oval, these have been bushed or welded up and re-drilled as appropriate, currently the reverser lever is in position, but will be removed to allow all parts to be cleaned and re-painted before re-fitting again. Work progressed on the cab windows with a start made on making a set of hinges for the front windows. Work has continued on making cladding for the valve covers, this is one of those jobs that sounds easy but can be time consuming, but rewarding when it is finished. We have also looked at the lubrication pipes that still need fitting to the axleboxes to see exactly what we have that is re-usable and what will need to be replaced.

7th February 2010

The piston gland stuffing boxes have been made, one has now been fitted. New studs to hold the piston glands have also been made. Preparations are under way to fit the reverser quadrant, this has involved making new fitted bolts so that the brackets can be fitted to the side of the right hand tank. One of the pins that connects the die block to the intermediate valve rod had been damaged, a replacement has been made, and now awaits hardening and grinding. The cab shutter runners have had new mounting studs made allowing us to fit one shutter, we will be having to make new shutters in the future.

31st October 2009

Since the last update on of the bearings for the back set of rods has been re-metalled, and now awaits machining. Work has taken place on the cab beading and several other small cab items such as the hand-brake chain.

Today saw more work on the boiler with 32 out of the 82 stay holes tapped out on the front tube plate. Also taking place today some of the cab window frames where taped having previously been drilled.

4th September 2009

Last weekend saw the 4th rod fitted, so now we have the front two pairs making a 2-6-4. The next set of rods need the bearings re-metaling and machining before they can be fitted. We have also been running the bar raising funds to enable more work to be done on the boiler.

14th August 2009

The first week of August was Didcot's work-week where volunteers can come and work for a holiday, it was good to see both some regular and new faces, hopefully everyone had a good time and we will see them next year!

Over the week various smaller tasks were under-taken, these include work on the window frames, fitting the 3rd water valve and associated pipes, some work on the left hand pipe between tank and bunker, grinding of a knuckle pin, back window catch and the cylinder cock linkage. As well as work on the 72 we did some work on swapping compressors over, changing brake blocks on the 38 and a few other jobs round site. There were other groups round site working on all sorts of other things as well. As well as all the work people had the chance to drive 5322, go on a trip and socialise in the bar.

16th May 2009

Last weekend saw the front pair of rods fitted, this may sound easy, but can only happen because of a lot of previous work.

Front rod on 7202

Work continues on the next pair of rods, unfortunately it seems we will have to remove the spherical bushes as they are not revolving properly, these are in a brass cage that is in two halves, this is then pushed in to the rod and locked in place with a threaded stud that is riveted over. The stud has been removed from one rod, but time prevented the bush being pushed out.

7th May 2009

For Didcot's "All in a Days Work" event we ran the bar again to raise money for 7202, this time we had 7202 just outside, with 3822 and 6697.

7202, 3822 & 6697

Unfortunately we were not able to fit any of the rods before 7202 was on display, but we hope to be fitting the front pair this weekend.

Work has started on the balance pipes that go between the side tanks and the bunker, these originally were a casting, but were replaced by a rubber hose and elbows. We are fabricating new ones to look the same as the castings as they are quite a prominent feature behind the foot-steps to the cab.

The rocker shaft cleating should have been fitted, when we were outside, but we forgot, knew there was something else to do!

19th February 2009

Last weekend saw more work on the rod bearings, with another one being machined, we will be looking to push some of them in to the rods next month, that leaves the thrust faces to do before the front rods can be fitted.

Rod bush being machinedPhoto © Rick Webster

The water valves are now finished, with the 2 main ones bolted to the engine, the operating rods, bushes and washers and handles have also been fitted, we just need to make the correct cotters that hold the handles to the rods. The rocker shaft is finally fitted, with just the final packing pieces to be fitted.

23rd January 2009

The bearing for the left hand rocker shaft have arrived, and just need final fitting.

Rocker shaft bearing in positionRocker shaft bearing Photos © Rick Webster

Work has progressed on the boiler, with the broken safety valve studs removed and a contractor has now ground the safety valve flange flat again. The weekend also saw the holes on the throat plate reamed, see www.rickwebster.co.uk for further details.

7202 with tanks and cab roof fittedPhoto Phil Neale

The 72 is seen here when the right hand tank and cab roof were fitted. Thanks to Phil for taking the picture while we were a little busy.

30th December 2008

The water valves have now been fully machined, and just await final assembly with grease. We have the chance to get some of the boiler mountings ground at the same time as several other boilers so we have spent time removing broken studs from the safety valve mounting in preparation for this.

25th October 2008

The tank has been fitted to the engine, and the roof put in place, although there is still some work to do on the cab roof to make it fit correctly. I would put up some pictures but as I was involved with the work I did not get a chance to take any pictures.

Work has progressed on the rocker arm covers, these should be ready to fit. A new bearing for one of the rocker arms has been ordered and will allow some more motion to be fitted.

17th August 2008

The final rivets have been fitted to the right hand tank of 7202, there is just the matter of ensuring it is all water tight now, then fitting plates over the side access holes created by BR then it can go back on the frames until we want to put the boiler back on.
Work is progressing else where with the insides of the 2 remaining water valves having been cast, we are now awaiting delivery of these items so we can machine them, then fit them along with the associated pipes from the bunker.

17th May 2008

Last weekend 7202 was taken out of the shed so that we could take the tank off to get at areas we can not get to while it is on the frame, this event took all day as it involved shifting all of 3 road of the shed, and works as well a 2 road in the work, taking the tank off and putting it all back!7202 in the daylight

Photo © Rick Webster

27th April 2008

The top of the tank is now riveted in place, we hope to fit the beading in a few weeks, along with the lifting eyes, after that we can take the tank off the frames to get to the parts we can't when it is on them.

Tank top

The front rods have been partially readied for fitting of the bushes, the photo shows one of the spherical bushes that allows sideways movement of the rods, this is a feature that was rare on GWR engines, and not normally visible as it is hidden by the next rod.

Spherical rod bush

29th February 2008

Since the last update the right-hand cross head has been re-fitted, the vacuum pump drive will be fitted once the tank is out of the way and the pump fully aligned.

Work has started on the front pair of rods, with the bushes being removed, most are now metalled and some have been machined. Once this is complete the front rods can be re-fitted.

Work has continued of riveting the top of the tank, but it relies on someone being inside to knock the rivets over, working in a confined space means that we have to stop so that legs can be stretched. The front section of the tank has been done, including the filler. The front section of beading has been fitted, but not yet riveted, the rear section can only be done once the top is fully riveted.

Work has started on the pipe work from the bunker to the 3, yes 3, water valves. Brackets have been made to support the main water valves. Parts are being cast for the water valves, these will then need to be machined to match the worn bodies that we have. Pipes have been made to replace the missing ones that connect to the 3rd water valve, this is to allow the tanks to be drained, and is visible underneath the rear of the engine, so will be re-fitted.

While looking at water pipes we have also looked to see what vacuum pipes we have, with a view to starting to fit this as well.

25th September 2007

The right hand cross-head is now ready for fitting having been machined as well as new fitted bolts being made for the vacuum pump drive bracket.

Work has continued on the right hand tank, the top is now fitted, just several hundred rivets to be fitted!

22nd June 2007

Two of the rod bearings have now been re-metalled and are ready for machining. The right hand cross head has also had some white metal applied and is currently mounted on the planner ready for machining. The jig that is in use is an original cross head machining jig, and the belt driver planner came from a GWR shed in the South West.

Further work has taken place on the right hand tank in preparation for fitting the tank top. Work has also involved working out where the ATC conduit fitted, the original was missing so some has had to be made from rescued imperial conduit.

17th May 2007

Over the last weekend 7 out of the 8 coupling rods bearings were pushed out in preparation for re-metaling. The remaining bearing does not need any work doing on it. Work was also done checking the right hand cross head to ensure so that once it has been re-metalled and machined that we are able to fit the pump connection straight up to it.

Over the bank holiday weekend we ran the "Black Python" real ale bar see here for details.

20th April 2007

Most of the recent work has involved cleaning the boiler for inspection and preparing to work on the main rods. Rick, one of our volunteers has set up an additional web-site for the boiler, see www.rickwebster.co.uk

Work has also taken place on a bar to help raise funds, if you want a beer join us at Didcot over the May bank holiday weekend.

1st December 2006

Work has progressed on the right hand tank, the back has been fitted, but still requires riveting, the new top has been cut to shape, with many more holes to be drilled before it is fitted and riveted.

Tank in 2006

The left-hand crosshead has been re-metalled, machined and put in place, although it is not connected to the piston yet as the glands still need some work.

The pipe-work for the ATC gear is being located and fitted.

Work is continuing on the front and rear cylinder cladding.

11th August 2006

The cylinder cocks that are connected to the cylinders are now fitted, the remaining 2 for the valves will not be done yet.

We have had a new steam fountain cast, this is now being machined, this is the largest single gun-metal casting that we will require.

The left-hand tank has been placed on the engine, this was done because the trolleys that the tank was on were required for the frames for the County Project.

13th June 2006

Both of the pistons had their rings fitted at the weekend and were put in to the cylinders, no easy task when you consider that they heads are over 19" diameter and 4" thick, even if they are hollow, and the rod is about 5' long by about 3" diameter! Once the pistons were installed the covers were fitted along with their copper rings, again not exactly another light item.

Both cylinders now have the side and bottom cladding fitted, this now allows the cylinder cocks to be fitted in the near future along with the front piston relief valves.

12th May 2006

The left hand tank is now ready for fitting, we are just waiting for the next big shunt. Items such as the air vents and water level indicator will be fitted when the tank is upright on the engine to reduce the chance of damage. The back of the right hand tank is being prepared for fitting with large sections being supplied ready folded to replace existing parts that have rusted away.

Most of the side cylinder cladding sheets are ready for fitting, hopefully one side will be completed this weekend.

While progress has slowed down in the last month work has been done on several other areas on site, including a trip to Eastleigh to get some machinery.

28th March 2006

The left hand tank has had the two pipes that go through it fitted using the traditional method, this being expanded in place rather than welding. The inside of the tanks has had tar applied on the joints and several coats of bitumastic paint applied, then the access holes where welded in place, all that remains is several coats of paint on the outside. The tank will be re-fitted to the engine when there is a major shunt, probably in the summer.

Work has continued on the areas of the cylinder cladding that need to be done while the engine is over a pit, this will also allow the cylinder cocks to be fitted.

Work continues on the little end bearings, hand scrapping ones that have been acquired to ensure a good tight fit that will last for many years without knocking.

Work has continued on the cab roof with the sliding vent being re-fitted so that it will work again.

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