Shed Turn - Lubricators & Drain Cocks

After a few days at work (the paid kind, involving sitting in front of a computer or talking in meetings) it's time for the highlight of the week, a day on the railway. Since we are still in the off-season, it's a day on-shed at Weybourne helping out with winter maintenance.

We're working on the BR Standard 4MT, and today it's the lubricators that are receiving some attention. Here's one, laid out in bits:

Some instructions on how it works. These have twelve pumps in each of two lubricators, one for the steam side and one for the axle boxes.

Here we can see the eccentric shaft (K) and the two carriers holding the regulating plugs (G) and the sleeve valves (E). The pump barrels (C) are in the blue box, and you can see their oil ports (F):

Here's one of the pump barrels, dismantled. You can see the non-return valve (H) and it's retaining cap:

Here's the reservoir, upside down:

This is where the lubricator fits on the 4MT.

Underside view of the reservoir with the pump barrels in place:

When complete, each pump has a pressure tight cap:

The view from the inside. the greenish bobbins are the guides for the carrier (W).

Now we are stuck. The camshaft is slightly damaged at the keyway, which has allowed much of the small movement from the driving ratchet to be lost. The camshaft needs to be repaired before we go any further:

So, it's on to another job. These are the cylinder drain cocks on the left hand cylinder; each cylinder has two, and there is a further drain cock on the steam chest. Their purpose is to drain water from the cylinders (when they are cold, for example) to avoid damage from hydraulic lock.

We know these are weeping steam, so they need to be cleaned out and the seats inspected. They are pilot operated by steam from another valve which in turn is manually operated by the driver:

Here's a diagram:

The inspection caps are very tight. We need a vice, a big spanner and a copper hammer to loosen them:

Here's the piston from one of them, covered in burnt steam oil:

Here's the rest of it:

Having stripped and degreased all four, it's a waiting game again while the piston sealing faces are refinished in the machine shop. Back to the lubricator, and we can strip and clean the ratchet drive:

Elsewhere in the shop, fitters Bob and Paul are removing the smokebox door. It's dropped recently and is difficult to close:

It's off!

The 7F is still have spring work. This simple hydraulic press has been adapted to measure the spring force against deflection:

Outside in the mist, the B12, Y14 and Ring Haw await their turn in the shop. The 4MT is getting all the attention, as there will be a yellow service for Spring Half Term at the end of February.

Shed Turn - Piston Valves

After the Mince Pie Specials finish at the beginning of January, there are no more service trains until the February Half-Term - but I still need my railway fix.

Aside from the odd MIC, this come in the form of shed turns. there is a lot of maintenance to be done, inspections and repairs that can only be made out of season, when the engines can be out of service for a while. This produces a huge demand on manpower and volunteers are encouraged to turn up and help out in the loco shed at Weybourne.

Today I arrived at 08:00 for the start of the normal working day, to find the BR standard 4MT, 76084, undergoing a valve and piston exam. Both valves and both pistons are out on the bench and the liners can be measured up:

Every 28 running days, the loco boilers are washed out. The railway tracks the running days and brings the loco on-shed for the plugs and mudhole doors to be removed and the silt & debris hosed out of the boiler. These mudhole doors have been cleaned up ready to go back on:

This is a loco I have not had a chance to see in close up before.

This is 1982 Ring Haw, and she is an 0-6-0ST built by the Hunslet Engine Company, from Hunslet, now a suburb of Leeds. From the NNR website:

This locomotive was built by the Hunslet Engine Company in 1940 to work at the Nassington Ironstone Quarries near Peterborough which were opened that year. The locomotive was used for hauling iron ore tipplers out of the quarries, usually three to four at a time to the dispatch sidings to make up longer trains ready to be picked up to be taken away on the mainline. Here it worked with another preserved Hunslet locomotive (Works No 1953 Jacks Green).

Both of these locomotives worked at the quarry until 1970 when it closed and were therefore the last steam locomotives to work in ironstone quarries in England.

Ring Haw moved to the North Norfolk Railway (NNR) in 1970 and is currently on hire to the Spa Valley Railway at Tunbridge Wells until January 2020.

As the site says, for most of last year Ring Haw has been on hire to the Spa Valley Railway, so I've not seen her since I started as a volunteer in May 2019.

Here are a few pictures. She's got an extended regulator handle. I guess, as a shunter, you want to be able to drive from both sides. Notice the vertical injectors:

Damper levers and injector water valves:

Blower on the right I guess; not sure what the vertical pipe on the left is.

Pole reverser and vacuum ejector.

The gauges are all out for calibration checks. I guess those linked levers are for the whistle, or for sanders?

Most more modern locomotives use piston valves (rather than slide valves) to admit and exhaust steam from the cylinders. Piston valves, being round, are pressure balanced and do not suffer the operating forces of slide valves, with consequent effect on locomotive efficiency. This is how they are arranged above the cylinder:

Here's one of a pair from the Standard 4MT. You can see the nut retaining the valve bobbin to the spindle caked in carbon from burnt steam oil. In this picture, I have already removed three of the six iron sealing rings:

That's all 24 rings removed.

Just like in your motorcycle engine, the burnt oil gets in the ring grooves and causes the rings to stick:

In a two stroke engine, you peg the rings in place to stop them getting stuck in the ports. These pegs perform the same function:

It took me eight hours to get them all cleaned out...

More next time.

Winding Points - MIC

Busy days on the railway usually see us sailing up and down the line, under the watchful eyes of the signalmen at Sheringham, Weybourne and sometimes Holt as well. Less busy days might see the Weybourne and Holt signal boxes unmanned (or 'locked out') and the railway controlled by the 'One Train on Line' method. On these days, the run around at the end of the line involves the guard operating the points and signals at Holt from the ground frame.

Today, a group of us, mostly guards plus me from Steam Locomotive Operations were engaged in a refresher course on point operation by Stuart, one of the railway's Responsible Officers. The purpose of the course was to remind the assembled group on how points were operated in the event of power failure or other faults.

At Holt, Weybourne and Sheringham most of the points are electrically operated from the signal box or ground frame by an electrical point motor:

That roundish bit in the foreground is the motor; the rectangular box in the middle houses the reduction gears and the rack & pinion used to convert rotary motion into linear, to move the point blades:

At the far end, the square box houses the switches which tell the signalman the point has reached the end position successfully (or not...)

There are two bars passing through this box from left to right in the picture - both are attached to the point blades. The lower one operates the limit switches, and the upper one is provided with cut-out sections which mesh the a third bar, passing through the box from top to bottom - this is the 'facing point lock'.

The picture above shows the various rods connecting the switch box, locking bar and point motor to the moving blades.

The facing point lock bar can be seen emerging from the end of the point motor. This one is unlocked:

Manual and electric points operated from the signal box feature three stages of operation - unlocking the blade, movement of the blade, and locking the blade again. In the signal box a manual point is operated by a black lever, and locked with a blue lever - the lock prevents the blades moving under the pressure from the train. An electric point is operated from one lever which is painted blue and black.

When operating an electrical point, or manually winding it, roughly one third of the movement unlocks the point; the second third moves the blades, and the final third locks the point again. When manually winding the point you can feel the weight of the blades in the middle third of the movement.

An electric point is manually wound using a lever which may be obtained from the associated signal box or ground frame. It is used in a square socket (almost square actually), hidden under a padlocked cover on top of the motor. Loco crew members should have the key with them!

To wind the point, the red painted lug needs to be moved out of the way of the lever socket - moving this lug disconnects the supply from the point motor. When the lever has been inserted, winding the point is straightforward though it must be remembered to wind the lever until it stops such that the point is properly unlocked, moved, and locked again:

When the movement is complete, the lug is re-positioned and the supply reconnected by grasping the reset knob, pulling it out and pushing it in again:

It should be noted that if the point is being hand wound through reasons of power failure, it is not unlikely that the failure may extend to the whole ground frame. If that is the case, the ground frame cannot be operated, which means the signals cannot be operated either.

In this event, the matter is significantly more serious since signals will prevent the train movement. The Responsible Officer must be called for permission to pass signals at danger; in practice, any failure should be reported. The RO will provide permission for the movement to take place if it is safe to do so but it is likely that several permissions will be required for the movement so it is wise to keep the phone line open until the whole run-around is completed. It should be noted that these are safety critical communications and written procedures apply.

A word on hand points:

A hand point, operated from a lever beside the point, can be driven through in the trailing direction, which will change the state of the points.

To fix the state of a hand point, clipping and scotching is used which holds both moving blades in a given position, removing any risk of derailment or preventing a route being set.

Turn 17 - Third Man on the 4MT - firing 3 trips

An early start this one - a Mince Pie Special timetable with four trips starting at 10:30 means I have to sign on, with Fitter Paul, at 05:45. It's a while since I have done a daytime turn and I am looking forward to it.

Today we have the British Rail Standard 4MT, one of the most modern and easiest locos to work from our NNR fleet. I climb aboard, put my bag on the fireman's seat and start the basic checks. There's almost a full boiler, as indicated by the two gauge glasses; one of these is weeping from the bottom gland which is easy to fix especially when the engine is cold.

Next stop, the firebox. The stays, tubeplate and fuse plugs are all good but the brick arch looks like it hasn't much life in it. Not being an expert in these things, I may be wrong but in any event in a few days time the loco will be out of service and in the shed for winter maintenance.

After that, It's time to clean the smokebox. There's a lot of ash in here, since the day before she will have done six round trips - I take two barrow loads of ash to the pit.

Fitter Paul lights the fire.

Later on when the fire is well under way I notice that the smokebox door is hissing - I didn't clean the seal and a bit of ash is preventing it from closing properly. I must remember that for next time.

Lamps next. Today, we don't have to dispose the loco because there are two Norfolk Lights Express trains after our 4th trip, and we will be relieved on the way down at Weybourne. By then, it will be getting dark so today we will need two paraffin lamps. I've got these ready and they are full, but I must admit I forgot to trim the wicks:

I do the other fireman's checks - flags, spare gauge glasses and seals, fill the bucket but there is not too much to do on the footplate so I climb up on the running boards to have a look at the paint - by torchlight, as it is still dark.

These BR Standard locos have wide running plates which make it very easy to get around, and they are very high compared to older designs. It means that you can easily clean the top of the boiler without ladders. I have a bucket of paraffin with 25% bearing oil in it which brings the paint up beautifully and doesn't take very long:

When I have finished both sides, it is starting to get light and I can see what I am doing. Fireman Josh and Driver James are here now; my next job is to pull some coal forward to allow Josh to build the fire. Next, we can go on the ash pit to look at the wheel bearings.

One of the Driver's duties is to see to the bearing cups on the motion & wheel bearings, and the cylinder lubrication using high viscosity steam oil, which is like thick honey when cold. It's the fireman's job to make sure the oil bottles are full:

When he's done, we can clean the ash pan:

This is the view through the front damper. I'm about to wash the ash and someone above will open the doors; on this loco, it's quite difficult to get the rear spark screen off - with the damper open, you can wash down the ash from the front which is much easier to get to. Without getting too wet, I put the front spark screen back on and call for Josh to close the damper.

Next, it's my turn to get changed and when I return to the engine I find it in the headshunt with driver James operating the hand point to let us out of the shed road. Fireman Josh has used the ground frame to let us onto the main running line, and I walk down to reset the ground frame when the loco is out of the yard. Today, there is a hiccup - when the loco has moved out the section and I reset the point lever, the point does not give me the correct indication that it's in position. This means the ground frame cannot be reset, I cannot move the loco and no-one else can get out of the yard...

We elect to call the RO to tell him what is going on, and to go and hand-wind the point. It goes into the correct position and eventually gives us the right indication and we can be on our way. We speak to Roger from the S&T department to ask him to check it later in the day. We will stop at Weybourne for him to check it, since he will need the Long Section Staff which will stop us moving the train.

The trip down proves uneventful; I make a plan with Fireman Josh to fire two trips - starting with the second trip when the engine is warm. We stop for breakfast at Sheringham, and I spend half an hour trimming the coal which is very high on one side of the tender.

We make a round trip, settling in and enjoying each other's company - it's great to have a daytime turn for a change. I call the hazards & signals while Josh gets to grips with the fire.

When we are back at Sheringham, Josh hands over the shovel and it is my turn. We only have about twenty minutes to run around and take on water which James and Josh deal with while I build the fire up. I'm pleased that after my allotment shovel practice I can hit the front of the firebox quite easily, but 76084 has a very short flame scoop which makes it easier. I'm also lucky that I don't have to control the fire for long before we are off, and I feel confident enough to call the signals and pick up the staff on the way while Josh keeps an eye on things.

In the end, I fired three trips - staying on the shovel for the rest of the turn. I'm very grateful to Josh for letting me do that, since after three round trips you can really get a feel for what you need to do since you are watching the fire, the boiler, the driver and the road all the time. Once or twice I forgot to check the fire door position and had a lot of black smoke belching from the chimney - after firing, you close the door to 3" gap and check the colour of the smoke - you can then adjust the door to add more or less secondary air; you can leave door wide open to bring temperature down. I blew off on the second trip being a bit enthusiastic with the shovel getting ready for the 1 in 80 ascent up the bank; I was surprised at how the draught lifts the shovel; I learned to shovel a lot of coal at the  beginning of an ascent and use draft to burn it. I found I could use the dampers to control temperature.

More than once, people have told me to fire slow and steady; James winced once or twice when my rhythm was getting a bit ragged and I smacked the shovel into the firehole ring but for much of the day, I felt like I was in control and had a great time.

In this picture, I'm hanging out of the fireman's window as we run around at Holt, relaxing. The fire is burning through (hardly any smoke, see?)

In this next picture, I'm climbing back on board as we ready ourselves to run around at Sheringham:

Running around at Sheringham

As the timetable today is for four Mince Pie specials followed by two Norfolk Lights Express trains, we handover to a relief crew on our last down trip at Weybourne. there's no disposal for us today and we can wash up and go home.