South Tynedale Railway NAKLO Blog

Welcome to the South Tynedale Railway NAKLO blog

Our blog concerns the story of the rebuilding of our polish built locomotive ‘Naklo’. Kindly funded by The Power to Change Community Business Fund, the locomotive’s main frames and tender are being rebuilt in our own workshops in Alston. Meanwhile the all important boiler, was rebuilt by TRS Boiler Makers in Derbyshire.

Our story starts in August 2018 once the boiler had been removed and shipped off as a template for a new boiler, work started on stripping down the locomotive to its component parts so its condition could be assessed and plans made for the necessary repairs and refurbishments.

31.08.2018 Having already removed the connecting rods and wheels, Naklo’s mainframes are under the lifting gantry at Alston. A crank from the weighbar shaft sticks up in the air as the team prepare to remove the remains of the valve gear
05.09.2018 and the strip down is gong well with the right hand cylinder being removed from the frames.
By the end of October 2018 the boiler begins to take shape at TRS boilermakers in Derbyshire. Here we see the boiler’s new backhead
Elsewhere in the works the firebox outer wrapper is being made, end view and side view below

Back at Alston the stripping of the main frames is complete and the frames now stand
on a bogie flat for assessment and further restoration.

23.10.18 The next step will be needle gunning to reveal the extent of corrosion and the extent of any necessary repairs.
23.10.18 End view of the frames
25.10.18 Meanwhile on the milling machine work starts on machining some axlebox bearings

Moving into November 2018 , the frames have been needle gunned and new metal has replaced areas where corrosion has taken hold.

The two shots of both sides of the mainframes show signs of new metal in the footplate outriggers and large sections of the front footplating having been replaced

Christmas time brought running of the STR Santa trains and the Christmas break.
In January 2019 reassembly of the Naklo’s frames has begun, with the cylinders now back on the frames. Work has started on the tender. the severe corrosion of the tender tank means this will need to be replaced. As we shall see in the future corrosion of the tender frames will also need a lot of corrective fabrication.
As originally acquired from Poland Naklo had side tanks, in an earlier rebuild these were removed and water was carried in a tank on the tender. As this reduced the adhesive weight of the locomotive, the tanks are being re-instated and the new tender will now have spaces for water, fuel and a battery compressor compartment for the train’s air brakes.


11.01.2019 The reverser, reach rod, weighbar shaft and cranks have been trial fitted on the chassis.
16.01.2019 With primer now applied to the frames, the cab has been temporarily placed in position to help with aligning the base for reinstatement of the side tanks on the left hand side of the frames
16.01.2019 Work continues on the fabrication of Naklo’s footplating
16.01.2019 The project team have now turned its attention to the stripped down tender frames. As designed the tender had a well in the tank between the wheelsets, the rectangular box in this shot. As water was in contact with the frames, this has caused a lot of corrosion.
16.01.2019 The corrosion here doesn’t look too bad perhaps, however when we get to the fixings for the couplings and the drawbars at the ends of the tender chassis, there is more corrosion to deal with.

Towards the end of January fabrication work is the main activity with Naklo’s side tanks being made as well as the new tender body.#

31.01.2019 The structure of the left hand side water tanks start to take shape.
31.01.2019 Both tanks are taking shape and the large brackets to support the smokebox have been trial fitted
30.01.2019 The tender body takes shape 1
30.01.2019 The tender body takes shape 2
31.01.2019 a day later its a 3 sided box, the box in the floor is the outlet for the tender water supply.
31.01.2019 Across the workshop the smokebox is being prepared to fit to the boiler when it arrives.

Early February was a very important day for the Naklo project, the completed boiler was delivered from TRS Boilermakers in Melbourne Derbyshire.

06.02.2019 Naklo’s new boiler sits on the delivery wagon in the workshop yard in Alston
06.02.2019 The new boiler is sitting on a bogie flat on the unloading ramp, admired by STR staff members Kim and Nicola.

06.02.2019 Whilst resting on its side in the workshop this image shows the backhead with the builders plate in the shot
06.02.2019 This shot shows the boiler lying on its side ,looking towards the dome with the firebox to the rear.

After the excitement of the arrival of the boiler fabrication work continues.
The three photos that follow show the tender body and components being fabricated

20.02.2019 Tender fabrication 1
20.02.2019 Tender fabrication 2
20.02.2019 Also being fabricated in the workshop is a new ashpan for the newly arrived boiler.
20.02.2019 On the milling machine work continues on the axleboxes

Fast forward to March 2019, the boiler has been mounted on the mainframes, the new side tanks are finished, have been test fitted and temporarily removed to allow access for other work. The smokebox has been fitted, a new smokebox door and baffle has been skillfully fabricated and turned on a lathe to ensure a parallel fit between the smokebox and door. The ends of the tender frame have produced some surprises with double
thicknesses of plate, that have provided a harborage for moisture and consequently rust!

11.04.2019 These rusted plates were laboriously removed from the riveted ends of the tender frame
Between the plates there was a large amount of rust.

Work has been going on to create the steam inlet and exhaust exhaust pipework which takes steam to and from the cylinders.
Curved exhaust pipes have been carefully fabricated from small sections of pipework to provide a route for low pressure exhaust steam from the cylinders to the blastpipe.
A hole in the blastpipe has been repaired and pressure resistant pipework has been fabricated to take boiler pressure steam from the boiler to the cylinders.

06.05.2019 One of the exhaust steam pipes being checked for fit, after being carefully tacked together from 9 different pieces of pipe
20.05.2019 Later in May here are both exhaust pipes bolted to the cylinders and blastpipe. The blastpipe has had a hole repaired ( the shiny bit )and the bolts holding the smokebox to the smokebox saddle brackets are now in place. Behind the exhaust pipes are the two pipes taking live steam from the boiler to the cylinders.

In May the pipework for steam to and from the cylinders was being completed. In addition the fabricated smokebox door was mounted on the lathe and the circumference trued up to give a tight fit against the smokebox.
In May also the tender was turned upside down and the pair of unmatched wheels removed from thier axleboxes. This is some of the evidence, that when built in 1957 by Fabryka Lokomotyw Imf Dzierzynskiego, Chrzanow, Poland Naklo was a bit of a ‘bitza’ locomotive made from components that were readily to hand .
06.05.2019 With the wheels removed the alignment and wear on the wheels and axleboxes could be assessed.
17.05.2019 With the axlebox horn guides removed it was time for some paint on the tender chassis!
May 2019 After a lot of work, the ends of the tender chassis had been rebuilt with riveting replaced, with a combination of fabrication and bolted construction.

June sees the tender body nearing completion

02.06.2019 Work on the tender body continues with the coal rails being welded in place in this shot.
02.06.2019 The side profile of Naklo begins to look like a locomotive. Note the fabricated covers over the inlet and exhaust pipework as it exits the smokebox, now fitted on both sides. The handbrake screw leans against the edge of the rear footplating.

July – sees work focusing on wheels, axles and axleboxes.

22.07.2019 Tender wheels get thier final coat of paint with the axles ready to mounted on thier new bronze wheel bearings, produced for us by William Lane Foundry in Middlesborough, who have been producing castings since 1862.
22.07.2019 Naklo’s main bearings only need oilways machining in the bearings and they will be ready to fit.
22.07.2019 Coal rails now complete on the tender, new footplating under the RH side of the smokebox.

August – Work starts on the cab.

12.08.2019 The side sheets, back sheet are fitted and the roof supports and part of the roof is being test fitted.
12.08.2019 The balance pipe between the water tanks has been fitted.
The locomotive wheels are getting thier final coat of paint.

September – The tender gets ready for its brake compressor to be fitted and is mounted on its wheels. Naklo’s cab heads towards completion. Naklo’s driving wheels visit the lathe to have thier tyres turned.

14.09.2019 The compressor driven by an electric motor has been fixed into its mounting frame. It will be powered by a battery pack to provide compressed air for the train and locomotive brakes.
14.09.2019 Seen alongside the workshop pit, we see the tender on its wheels
14.09.2019 This close up shows the detail of the horn guides fixed to the frames by 6 bolts and the axlebox housing the bearings in which the axles rotate. The vehicle suspension is provided by the axlebox pushing against the leaf spring.
28.09.2019 The cab is nearly complete and is test fitted on the footplate. Note how the window shapes don’t match back and front, but that was how the locomotive arrived from Poland! See below
Naklo’s cab as it arrived 30 years ago in 1988
14.09.2019 Naklo’s driving wheels get turned to restore them to the correct profile.
Naklo has 6 driving wheels on three axles. The two outer axles have flanged wheels, to guide the locomotive on the rails, as the wheels in the lathe above. Naklo gives away its sugar beet railway background, as this photo shows, the centre axle has no flanges to allow the locomotive to travel over the sharp curves of a sugar beet line.
The axlebox bearings have had their oil ways cut into the bearings to provide lubrication to the these bearing that support the weight of the locomotive when its on it’s wheels.

By the 25th of October came the time to start fitting Naklo’s driving wheels. The boiler, tanks, and cab were removed and the chassis turned
upside down to allow the driving wheels to be fitted to the locomotive’s
main frames.

Here we see the inverted frames with the flangeless centre pair of driving wheels mounted in the main frames. Lurking in the left background is Green Dragon raising steam.
Behind the main frames sits the boiler on a flat wagon with the cab awaiting their return to the chassis, once the wheeling of the locomotive is complete.
Work is going well on the tender, this shot shows the new doors in the rear giving access to the battery back and compressor, which will power the train brakes. One end of the tender has draw gear fitted, with a Willison coupling in place on the rear of the tender frame.
Here’s a close up shot of the centre flangeless wheelset sitting in the upper main wheel bearings, awaiting test fitting of the lower half of the wheel bearing in the inverted main frames
A shot from the workshop’s public viewing gallery, the two remaining wheel sets sit at the side waiting thier turn to be mounted in the frames. The red coloured brake shaft has been fitted at the rear of the main frames. The original well tank between the cylinders will not be reused for water, but it will have weights added inside the tank to ensure the locomotive has adequate adhesion
Here’s a rather grainy shot of Green Dragon getting up steam, it had a trouble free run to Slaggyford and back on the evening of the 25th of October when it hauled the train for the railway’s Murder Mystery event.

2nd November 2019

By the 2nd of November all three wheelsets are in the main frames, with work progressing on fitting the lower halves of the wheel bearings.
Naklo’s brake gear is being fitted up, here’s a shot of the steam brake cylinder which operates the crank on the left providing steam powered braking for the engine.
Previously we mentioned the former well tank between the cylinders, here’s a close up shot of the interior of the tank, showing it’s internal baffles whilst the access plate is removed.

22nd November 2019

It’s 20 days on since our last posting, the driving wheels, along with the axles boxes and wheel bearings in the foreground, have been test fitted in Naklo’s main frames. The frames have been turned the right way up and have been undercoated and today your webmaster was amongst the team of volunteers who have been applying top coats of paint to protect the frames.
Here’s a couple of 3/4 shots showing the newly painted main frames

23rd November 2019

Naklo’s main frames got further layers of top coat today.
Hanging drying from the viewing platform, are smokebox supports and steam pipe covers, all having been painted with a special heat resistant coating
The components of the reverser were also painted in smooth Hammerite.

Whilst Naklo is stripped down there is an opportunity to see some of the parts of the engine always hidden from view.

Here’s a shot through one of Naklo’s steam cylinders, with the front buffer beam in the distance
With the steam chest cover removed, we see here the two steam ports through which high pressure steam enters the each end of the cylinder and the centre exhaust port through which it leaves the cylinders to be exhausted through the blast pipe and up the chimney.

Work is coming to a close on the brake compressor and battery pack installation in Naklo’s tender.

Yet to be prepared for painting, a handle and retaining catches have been fitted to the access doors to the compressor and its battery pack.
Inside, work is in progress on plumbing in the air compressor to the provide compressed air to operate the locomotive and train brakes. The battery packs that provide the power to drive the compressor’s electric motor, are strapped to welded lugs inside the tender to prevent them moving in service.

28th November 2019

Hanging drying from Naklo’s cab, are components of the reverser, live steam and exhaust pipework covers, all having had thier second coat of black paint today

29th November 2019

Work continued today on the tender’s air brake system. In the bottom left hand corner of this shot we see, peeping out from under the footplating, the pipework which will eventually provide air for the twin pipe air braking system. Above the compressor the engineering team have installed the air receiver that stores compressed air generated by the the compressor below, this has had its safety guard removed, to allow pipework connections to be made.
On the wall of the tender tank, the control valve for the air system has been bolted in place and awaits fitting of the pipework connections to the rest of the system.

06 December 2019

Outside the workshop in Alston today, there was much activity making preparations for the operation of STR’s first weekend of Santa Specials.
Inside the workshop, progress was also being made, with the first pair
of Naklo’s driving wheels, now fitted to the locomotive’s frames.

Here we see the front driving axle, one in two to go!
Looking through the spokes of the first axle we see the right hand axlebox, with its stamped identification markings, whilst in the background we see the lubrication pipe to the left hand axlebox
On the bench, the forced lubrication pipework for the remaining axlesboxes were being piped up, the grey material is plastic metal, used to secure the pipework in position.
Also on the bench the new pins that secure the two halves of the axleboxes, were being test fitted, the old worn pins are on the right. On the surface of the phosphor bronze bearing can be seen the channels, that carry lubricant to the axlebox.

There has been progress with the tender, air valves to feed the flexible brake pipes between the tender and the train have been fitted. These valves connect to the original tender brake piping. The tender’s compressor/battery pack doors have been trial fitted with opening handles, they were being welded in place this afternoon.

New opening handles in place on the tender doors
New air brake valves in place, connecting with original tender air brake pipework.

9th December 2019

Today work continues on Naklo’s tender and fitting the centre flangeless driving wheel to the locomotive’s main frames.

On the tender, the access doors to the compressor/battery pack compartment are almost ready for preparing for paint. The handles are now welded in position and the doors open and shut easily.

The pipework that feeds water from the tender to Naklo has been installed, ready to connect with flexible pipes to the locomotive.
With the leading wheelset already in place, the middle flangeless wheelset was being lifted in to place this morning in the STR’s Alston workshops.

18th of December 2019

Naklo gets its driving wheels fitted and preparations are being made to fit the springs and spring hangers.

Naklo’s driving wheels are now mounted in the locomotive’s main frames, top photo RH side, bottom photo RH side.
Here we see 5 of the 6 driving wheel springs cleaned and undercoated
Some of the spring pins and eye bolts have been refurbished ready for fitting.
Back on the workshop bench refurbishment of the remaining components continues.
After several coats of heat resistant paint, the smokebox support brackets have test fitted to the front of the mainframes

Work continues on the tender with a second train brake air reservoir fitted and some plating work on the front upper corners of the tender.

The red air reservoir for the train brakes has been fitted on the rear of the tender. The reservoir will be piped in with copper piping.
The two upper front corners are being fitted with additional plating, in this shot we see the LH side being test fitted before welding.

20th December 2019

On the Friday before the STR’s 3rd Santa weekend, work continues on Naklo’s tender and locomotive main frames.

In a previous post your webmaster misreported the work on the front of the tender. The top front corners of the tender were in fact, being turned into two useful equipment lockers. Here we see an exterior view of the left hand front corner.
Lift the lid and a useful storage area is revealed.

On Naklo’s main frames the locomotive’s springs and suspension components continue to be assembled.

In this shot the spring furthest from the camera is almost in place. Naklo has compensated springs, whose purpose is to even out jolts and vibrations due to irregularities in the track. The left hand side of the far spring is connected to a compensating link which connects the ends of two adjacent springs which pivot on a common pin which pivots on a mounting welded to the main frames.
On the bench we see more suspension components.
The long rod lying horizontally in front of the camera is a suspension push rod.
These rods transmit the up and down movement of the axleboxes through a circular hole in the welded main frames and bear directly on the underside of the springs. Some of the rod ends have had to be replaced due to wear, the shortest one nearest the camera has had its circular end replaced by welding on a new rod end, machined to the correct dimensions.

9th of January 2020

Into 2020 and here’s our new year update on the progress with Naklo’s rebuild.

Locomotive main frames

The four compensated springs for the leading and centre wheelsets are now fixed in position. The rear pair of wheels are sprung by two more springs that sit close to the ash pan between the frames. Work also continued today on connecting the axlebox lubrication pipes which will eventually be fed by Naklo’s mechanical lubricator.
The ashpan that was fabricated in 2019, has now been slotted in place between the frames.
Looking rearwards down into ashpan, the hole in the bottom through which we can currently see a red jack, will become the bottom of the ashpan in which the ash will be contained. The rectangular hole in the rear is for the damper to control admission of combustion air to Naklo’s grate.

Naklo’s tender.

The water pipe from the tender to the locomotive is now permanently fitted.
The lids to the tender lockers are now complete with domed locking nuts.
Work in progress in securing the train brake air tank, next step will be to complete the piping. Diesel locomotive ‘Old Rusty’ in the background, tank water filler to the right.
UThe air distribution valve, test fitted earlier, is now bolted in position ready to receive its air piping.

24th of January 2020

Naklo is back on its wheels and preparations are being made to return the boiler to the frames. We’re making good progress on the air brake pipework in the tender.

Naklo is back on its wheels with its springs and suspension components in place. Here we see the springs for the leading pair of wheels, whilst the springs for the rear pair are hidden between the frames. The boiler will sit on top of the ashpan at the rear of the frames. Later the ashpan will be clamped in place, where the frames have outward extensions above and behind the rear wheelset.
In preparation for its return to Naklo’s mainframes, the boiler tubes have been beaded and expanded
The mainframes sit waiting for the return of the boiler.
It’s not very obvious from a photograph, but a lot of work goes into piping up the air brakes in the tender, this job is now nearing completion

The frames didn’t have to wait long for the boiler, your webmaster was surprised to get an e-mail this afternoon, with two shots of the Naklo’s boiler back in the frames.
We’ll done to Steve and Chris our staff engineers at Alston workshops.

With the lifting frame straddling the engine the boiler is back in the frames.
The view from the rear, showing the firebox sitting snugly in the frames, once more.

6th of February 2020

With the boiler back in the frames, we’re beginning to fit the boiler with a multitude of pipework and boiler fittings, that are needed to gradually turn it from a rolling chassis into a locomotive.


The upper smokebox door clamps have been fitted with stops to prevent the clamps getting in the way when the smokebox door is opened and closed.


On the workshop floor waiting its turn to be fitted, is the regulator valve body and valve that will be fitted in the boiler’s dome
Sitting on the footplating is the regulator quadrant and the regulator valve spindle stuffing box ready to be fitted to the boiler backhead.
Clearly not to scale, the rod that fits inside the boiler, connecting the regulator quadrant to the regulator valve, also waits its turn on the long list of boiler fittings

Clack valves and thier boiler mountings

Naklo has combined clack and shut off valves that deliver the water from the injectors into the boiler barrel. Above we see the cleaned up valves ready for fitting. The shot above shows a clack valve mounting, both of these have now been fitted with thier mounting studs.

Boiler fittings
The workshop was busy today with preparatory work on boiler fittings.

Here we see work in progress on a steam manifold.
Earlier on in the day it was the turn of gauge glass fittings to be cleaned and examined.

14th of February 2020

Fitting the regulator valve

As I’m sure many readers will know the regulator valve on a steam engine controls the steam, that flows from the boiler to the cylinders to turn the wheels via the connecting + coupling rods and drive the locomotive.

Fitting the regulator valve is not a straightforward job, to quote our engineer Steve Race, “it’s the engineering equivalent of a complex medical procedure”.
The regulator valve is mounted within the very tight confines of the dome, it’s operated by a long curved rod attached to the top of the valve, actuated by a crank mounted on the regulator shaft which is mounted inside the boiler just above the boiler tubes and operated by an external lever mounted on the backhead of the boiler.
The long and heavy regulator shaft enters the boiler through a stuffing box on the boiler backhead. The most difficult task is to ‘lasso’ the end of the regulator shaft with a rope so it can be held in place, whilst the crank and rod that operate the regulator valve are attached, to complete the assembly.

In the photos that follow we enter the tight and compact area of the steam dome, only seen as times like this when a new boiler is being commissioned.

Lets get our bearings and see where everything is situated before we get down to details

Here we see the boiler backhead, with the main manifold and its shut off valve on top and the regulator, its stuffing box and open shut quadrant below.
This shot shows the regulator valve left of centre with the open topped pipe that supplies steam to the manifold behind it. The pipe reaches almost to the top of the dome to allow it to supply a steam supply that is as dry as possible.
Further down inside the dome it gets very crowded!
Naklo has a continental design of regulator valve, it’s design is quite different from those found on UK built locomotives.
The dome is sealed off with a large piece of boiler plate, many bolts are needed to resist the boiler pressure within. Note the hole in the middle for a lifting eye, its very heavy!

21st of February

Coupling rods

Work has started on the coupling rods and thier bearings.
Each coupling rod has a vertical hinge pin that allows the rods to
move to accommodate the vertical movement of the locomotive on its 3 axles.
Naklo’s coupling rods overlap by half a rods thickness at the point where
the rod is hinged. The hinge pin bearing needed replacing. In the shot that
follows, we see the hole in a coupling rod in which the bearing is mounted.
The bearings were seized in the rod and have had to be cut out.
Another progress report next week.

The circular hole in the rod has had the bearing cut out and is in the process of being shaped with a die grinder in preparation for fitting a new Hinge pin bearing
This is what was left of the bearing and its mounting after the seized assembly was removed form the coupling rod.
Sitting on the floor is a rod and some bearings waiting thier turn for refurbishment.
Another assortment of cylinder cover, crosshead, cranks and bits of the Walschaerts Valve Gear also wait thier turn in the queue! Later in the day a number of these rods were cleaned up with debris and paint removed. The precautionary marking of LH and RH was perhaps unnecessary, as all of the rods we’ve cleaned so far, are stamped left and right hand.

5th of March

Sorry, there was a bit more than a weeks gap between updates.
Re-assembly of Naklo continues, the firebars are in the firebox, the first coupling rod is being fitted, the damper controls are being assembled, a pillar for the handbrake has been made, the exhaust and inlet pipework is almost complete and the smokebox has had a smart coat of heat resistant black paint!

Here’s a shot of the firebars sitting on a pallet before installation. The firebars were cast by the William Lane foundry in Middlesbrough.
Not a very bright photograph but you can just see that most of the firebars are in place in the firebox.
The crankpins have been lined up and the first coupling rod on the right hand side of the locomotive, is having its bearings adjusted before fitting the rod in place,
In the previous posting we saw this rod end knuckle or hinge pin bearing hole having its seized bearings removed. A new steel bearing is now a very tight fit in the rod and has been further secured by pins to prevent it turning.
A lever with hooked slots in it sits in the footplate, awaiting connection to the rest of the damper set up.
This handbrake pillar will eventually bolted to the footplate to support the square threaded handbrake screw.
A shot we’ve seen a few times on this blog, the re-assembly of the inlet and exhaust pipework is complete with only the external sheet metal covers yet to fit.
Internal smokebox pipework re-installed.
The smokebox wears a new coat of heat resistant paint.

6th March 2020

Work on coupling rods continues.

The rear right hand coupling rod sits waiting on the crankpins whilst its bearings are adjusted.
Sitting on the Naklo’s mainframe are two more bearings waiting in the queue.
Naklo’s front lamp bracket has one bolt in place and one to go.
fitted some time ago and only now shown on the blog, is the single buffer that makes the contact point between Naklo and its tender.

7th of March 2020

Back in Alston again, today sees the rear right hand coupling rod in place and the re-assembly of the smokebox pipework almost complete.

The work on the RH rear coupling rod is now complete, bearings fitted and wedges adjusted.
The front RH coupling rod waits its turn for fitting, the forked end fits over the circular end on the right in the photograph above. The bearings for this rod were being worked on today.
All the smokebox locking dogs are in place, the lamp bracket is fitted and yet to be painted, the exhaust and inlet steam pipe covers lower right are next to be fitted.

11th March 2020

RH side coupling rods now in place
Another frontal shot of the completed smokebox

14th March 2020

The rear part of the LH side coupling rod is now in place
The front part of the LH side coupling rod sits on the floor with one of it’s bearings awaiting fitting W/C 16.3.2020

17th March 2020

The LH Coupling rod is coming together
Naklo gets its shed plate fitted. In standard gauge, British Rail days, all locomotives carried a plate showing the shed code of the shed to which they were allocated, the Alston engine shed now demolished, was a sub-shed of Blaydon shed and thus carried Blaydon’s 52C code.

4th of April 2020

South Tynedale Railway is following government advice concerning the current
Covid-19 virus, consequently restoration work on Naklo is suspended until further notice. We will bring you news of any further work on the locomotive as soon as it becomes known.

20th of May 2020

Good news, restoration work on Naklo re-started in early May, where Steven Race has been back at work for 3 days a week. The photos were taken on Tuesday 19th of May, they show the excellent progress being made on the rebuilding of Naklo’s pistons, slide bars and valve motion.

Pistons, rods, die blocks and cylinder drain cock rods.
In this photo we see both Naklo’s pistons and rods which have been machined ready to receive the piston rings which have been ordered from an external supplier. On the left hand piston is one of two die blocks made recently, they fit in the expansion links of the Walschaerts valve gear.
The thin rods with the cut outs in them, are the two new cylinder drain cock actuating rods. For comparison, one of the worn originals sits at the bottom of the shot.

Slide Bars
The slide bars for the crossheads have now been machined. The before and after shot below, shows an un-machined rod on the left and a newly machine rod on the right.

Crosshead slippers

The shot below shows one of the old worn crosshead slipper bearings. Steve made a new pattern for these, which has been sent to the William Lane foundry in Middlesbrough for 4 bronze new slipper bearings to be cast, which will be machined and fitted when the castings return from the foundry.

Valve Rods
These rods actuate the slide valves in the valve chests. The shot below shows one of the rods propped up against the loco. The threaded section at the bottom end of the rod is where it is connected to the slide valves.

Expansion link with die block plus slide bar.
In the photograph below we see one of the new die blocks sitting in the expansion link, with one of the machined slide bars propped up beside it.

General view on Naklo
Here’s a general view of Naklo as of Tuesday 19th of May.

More updates to follow soon.

28th of May 2020

Work continues on Naklo’s valve gear, connecting rods and pistons.
In the ‘old bits that need replacing’ department here are two piston rings now too worn to reuse, new replacements are on order and are expected soon.

The valve stem guides have been machined an fitted on both cylinders.

Left hand side
Right hand side

New Neck Rings, the bearings that support the valve rod at the rear of the cylinder, have been produced to fit the valve rods that have been in turn, machined, to remove any wear where the rod passes through the gland, before it enters the valve chest.

Lubrication grease nipples have been fitted to Naklo’s suspension.

Awaiting their turn in the refurbishment queue are rear cylinder covers with crosshead bar supports and two crossheads sitting on the sack barrow below.

6th July 2020

Cylinder covers – The rear cylinder covers which also support the end of Naklo’s single slide bar have now been fitted.

Right Hand Side
Left Hand Side
Here’s a shot of one of the front cylinder covers sitting on the buffer beam with thier gaskets

Combined clack/stop valve – These original valves, which allow water to enter the boiler from Naklo’s injectors, have been refurbished and now fitted to the both sides of the boiler to take the feed from the locomotive’s two live steam injectors.

Left hand Side
Right Hand Side

Piston Rings – The 4 new rings have been delivered, here’s a shot of an old ring on the left and sitting on top of a machined piston, two new rings in the queue to be fitted.

8th – 10th July 2020

Naklo gets its pistons with new piston rings fitted.

Steve Race our engineer at STR started fitting new piston rings to Naklo’s piston this week.
First task was to get the shiny new and very stiff rings on to the piston. The rings are first carefully
opened up and using lots of small pieces of hacksaw blade eased over the head of the piston and
into the two slots in the piston head which have been carefully machined to ensure the rings are
a sung fit, and able to withstand the forces acting on the piston.

A Piston head with its rings fitted.
The springy bits of hacksaw blades used to ‘persuade’ the rings on to the piston
Side view of the piston head. Like it’s much smaller automotive brothers, the piston ring gaps do have to be carefully positioned in the cylinder, not an easy task!
The Right hand piston went in first and here we see the end of the piston poking out of the end of the cylinder as the piston is persuaded to enter the cylinder.
Finally the piston sits in the cylinder bore.
The inserted piston seen through the front of the cylinder block.
In the automotive world its a fancy spring compressor, in the steam world a loop of wire is twisted to compress the two piston rings as the enter the cylinder.
Not to be left out of the story, here’s the piston rod poking out of the left hand
In the dark interior of the left hand cylinder sits the piston head.

Removing the crosshead drop link pin 10th June 2020

Having installed the pistons Steve’s next step was to work on the crosshead drop link. The diagram below, will help our visitors which bits of Naklo’s Walschaert’s valve gear, that’s being described

The key components of Walschaerts Valve Gear: this diagram has piston valves, however, Naklo
has slide valves.

  1. Eccentric crank (UK: return crank)
  2. Eccentric rod
  3. Reach rod
  4. Lifting link
  5. Lifting arm
  6. Reverse arm
  7. Expansion link
  8. Radius bar
  9. Crosshead arm (UK Drop link)
  10. Valve stem guide
  11. Union link
  12. Combination lever
  13. Valve stem
  14. Piston valve
The area on the right had to be heated to help release the pin.

Another focus for today was removal of the large pins that connects the crosshead drop link, (No.9 in the diagram above) to the union link an thus onwards to the valves via the combination link. The pin in question was tight press fit in the crosshead casting, the shot above, of the part of the crosshead that houses the pin shows signs of the heat, that had to be applied to help release the pin using our hydraulic press.
Looking at the drop link before we removed the pin the alignment of the pin didn’t look promising.

The steel rule is on the drop link on the base of the crosshead, The pin is clearly drooping to the left and not at all horizontal. Your webmaster was asked to point out the Stillson marks occurred before the latest re-build!
This shot shows the drop link in the works press ready to remove the pin.
Here’s the first pin extracted , the plain press fit section to the left, drop link bearing in the middle and threaded section to the right. Needless to say pins in this condition must be replaced.

13th -18th June 2020

With the crosshead drop links sorted, the next job was to start assembling the RH side crosshead.
Here we see the start of the assembly process, with the piston rod mounted in the crosshead supported by a jack and a block of wood.

The top and bottom crosshead slipper bearings that support the crosshead as it slides on Naklo’s single slide bar arrived back from William Lane Foundry in Middlesborough.
Below we see a shot of – top – the pattern for the slipper bearing casting middle – the the raw Phosphor Bronze PB2 casting before machining and lastly one of the original worn bearings, all sitting on Naklo’s footplating.

The timely arrival of the castings meant that machining operations could get started on the slipper bearings. Here we one of the castings being machined on the milling machine.

Here’s a close up shot of the milling cutter doing its work.