Preservation Moves in Brazil

After the retirement of the two 7109-like Sentinel locos in Brazil in October 2014, they have now been moved from the Amsted-Maxion Steelworks, Cruzeiro, to a location for safe storage and, hopefully, restoration with future use.

166 (8400) en route (Photo by Bruno Sanches)

167 (8398) ready to unload (Photo by Bruno Sanches)

8398 and 8400 in their new home (Photo by Bruno Sanches)

The new home is at the ABPF - Regional Sul de Minas (Brazilian Association of Railroad Preservation). (For those whose language skills are as apologetic as mine, google can translate pretty well!).

Sentinels 8398 & 8400 Retired

I was saddened to hear this week from my contact in Brazil that the two other remaining pre-war double-engined Sentinel locos ceased their long working career on October 31st 2014.

Sentinel 8398 at work at Amsted Maxion Steelworks in Cruzeiro on 2nd Mar 2012.
Photo James Waite.

Discussions are under way to put the two into preservation; however, I don't know how things are progressing. I hope to have more news in due course.

Sentinel 8400 at work at Amsted Maxion Steelworks in Cruzeiro on 2nd Mar 2012.
Photo James Waite.

These two locomotives were manufactured by Sentinel in their works at Shrewsbury in 1930. They are two of three originally delivered to the Sau Paulo Railway, Brazil; I believe attempts were made some years ago to convert 8399 to diesel but without success and the result was scrapped.

In Search of the lost Nutty

'Nutty' is one of a peculiar breed of specialised locomotives that Sentinel made in the 1920s for brickworks use. Their prime requirement was to be very squat in height; very, very squat (5'2" in fact)!

Nutty lookalike - Works number 7243 built in 1928
(Photo from Sentinel Drivers' Club collection)

Built as works number 7701 in 1929 to a 2' 11" gauge, Nutty was one of about five constructed using steam waggon components.

In order to reduce the height as much as possible, the engine was mounted horizontally and the boiler very near to the ground. It also made driving a remarkably intimate experience!

No room for foot-plate passengers!
(Photo from SDC collection)

Neither of the above photos are actually Nutty; however, the next one certainly is.

Nutty in August 1971 at the Welshpool & Llanfair Light Railway
(Photo SDC collection)

The inner workings are clearly visible if you click to enlarge the picture.

I became aware of Nutty through conversations with curators of the Narrow Gauge Railway Museum in Tywyn, Gwynedd, at the terminus of the Talyllyn Railway (where I can be found volunteering on occasions). Nutty is actually owned by the NGRM but it never seems to be found anywhere near the museum!

Although originally built to a gauge of 2'11", it was re-gauged to 2'6" some years ago and it ran on the Welshpool and Llanfair Light Railway for a while. Since that time, I do not know exactly where it has been but I'm led to believe it has spent time at Railworld in Peterborough. In 2012, it made its way to the Leyton Buzzard Railway where it is on display at the Stonehenge Works station.

I visited the LBR on Wednesday 16th July 2014 and was made very welcome indeed. I wanted to poke my digital camera into Nutty's various nooks and crannies to assess its general state. I now have around 170 photos, not all are included here!

Nutty under cover at Stonehenge Works

Yes, it is chain-driven!

Side-on view

Cab internals showing the boiler

'Under the bonnet' view showing the engine beneath the water tank

Engine, water tank and boiler feed pump

Bijou accommodation for the driver!

There are clearly a number of components missing and regrettably I omitted to enquire if they existed. However, it was a good day out and many queries answered as to the construction of this strange locomotive.

Now who volunteers to restore Nutty, reduce the gauge by another 3" and run it on the Talyllyn railway?

April 2024: I've been asked for an assembly drawing of Nutty for modelling purposes. Regrettably this request came about a year ago so please accept my apologies for not monitoring blog comments.

I hope this drawing will help:

See my Reference Material page for information sources.

Sentinel Conversion Loco (and no clothes!) (4)

Mike Hart has sent some more photos about his progress restoring Gervase at Elsecar Heritage Railway.

Mike comments (28th Feb. 2013): "Today we shunted Gervase out of the shed at Great Central Railway so it could go on the pit to be weighed and have its springs adjusted. We will leave Gervase with her clothes off for ease of access and any final adjustments when we steam her up for test running. Nearly there - at last!"

These photos were taken outside Locomotive Maintenance Services at The Great Central Railway, Loughborough. Earlier photos (2), Earlier photos (1).

Front view showing vacuum brake and steam heating fittings

Off-side front

Near side showing mechanical lubricator mechanism
Compare with earlier view

Single Chain drive and gear-case
This is very different to 7109's dual chains and twin gear-cases

Off-side rear

Now how about a signal red under-belly for 7109?

Sentinel Conversion Loco takes shape (3)

Mike Hart has been keeping me informed about his progress restoring Gervase at Elsecar Heritage Railway.

In my first article, Gervase was reported as steaming for the first time in 50 years and that Locomotive Maintenance Services at The Great Central Railway, Loughborough, would be completing the restoration work.

These photos were taken by Mike during activities at Loughborough on 7th February 2013.

New Side-rodding in place

Rear Cab View

New Axle Boxes to take the white-metalled brass bearings

White-metalling in progress

6-Feed mechanical lubricator for axle-box crowns

Near-side view with cover removed

There are some dates already pencilled-in for Gervase's first few steaming appearances this year. I'll help to spread the word when the pencil has turned to ink!

Keep up the good work Mike.

Sentinel 8398

Pre-delivery Works photo of Sentinel 8398
(Source: Sentinel Patent Locomotives 1931)

Following on from some brief correspondence between the Sentinel Drivers' Club and International Steam's James Waite, I've found some more video and pictures of Sentinel 7109's younger sibling in Brazil in 2009.

Courtesy of Andreas Illert and International Steam, I've appended the various links in Remaining double-engined Sentinel locomotives.

Sentinel Conversion Loco Steams Again (2)

After posting the article on Gervase's restoration progress, I found a couple of photos of Gervase of old in Tony Thomas's photo collection.

Gervase at Tenterden 21st October 1969
Photo Courtesy of Tony Thomas

Gervase at Standard Brick Co., Redhill 13th January 1951
Photo Courtesy of Tony Thomas

Sentinel Conversion Loco Steams Again (1)

Mike Hart from Elsecar Heritage Railway, recently announced that his current restoration project, a Sentinel Conversion Loco named Gervase, had steamed again on June 30th 2012 for the first time in 50 years.

Gervase (1) photo courtesy Mike Hart

As well as preparing the boiler for its final certification exam, the engine unit was run, the vacuum and steam brake equipment was tested and the steam heating and all the other bits and bobs checked out. At the end of the day, a pleasingly small snagging list was left to sort out.

Gervase (2) photo courtesy Mike Hart

At the end of July the loco was planned to be moved to the railway workshops at The Great Central Railway, Loughborough, where Locomotive Maintenance Services would make and fit new axle boxes and horn guides, recondition the side rods and perform various other jobs to finally finish the loco’s restoration.

Gervase (3) photo courtesy Mike Hart

Mike’s aim is to have the loco operating at Elsecar by Christmas 2012 and ready for a trip to the Kent & East Sussex Railway Gala in May 2013 to celebrate the 50th anniversary of its first steaming at Tenterden.

Gervase (4) photo courtesy Mike Hart

Sentinel works no. 6807, Gervase, is the only known remaining potentially serviceable Sentinel ‘conversion’ loco. It was originally a Manning Wardle but adapted by Sentinel in 1928 to use a vertical boiler and vertical twin cylinder engine of steam road waggon design.

Although the cab and engine housings bear a resemblance to the Fry's type of 100 HP Sentinel, there the similarity ends - it has side rods instead of chains linking the front and rear axles.

This is a really interesting project and I am looking forward to visiting Elsecar to see it in action.

Click here for a couple of historic photos.

200HP Pre-War Sentinel Locos (2)

The 1920s were not well known for mass production and, of its type, Sentinel 7109 was the first of not very many, only 14 in total. 7109 was actually a basic design around which variants and enhancements could be made to suit particular customer's requirements.

Two 200HP design variants were made to suit the Somerset & Dorset at Radstock where a low bridge required reduced maximum height. These were the Radstock Sentinels with their lowered cab roofs.

However, another pair of 200HP specials, with works' numbers 8147, 8148, was delivered in 1929 to the LNER. Eventually designated as Y10s, they were specifically intended for use on the Wisbech and Upwell Tramway.

On these, a second, front-mounted cab was added to make them capable of being driven from the front in either direction. Tramway standards of the time dictated that 'skirts' and 'cow-catchers' should also be fitted for public protection.

Twin Cab Design with Cow-catchers

Knowing 7109 inside out, I've always found these twin cab variants fascinating. In particular, being aware of what it's like under 7109's engine covers, it would not be a nice place to work! There are hot pipes and non-elbow-friendly protrusions all over the place! These locos were withdrawn from the W&U Tramway after only a short service and one can only speculate the reason. However, subsequently, they were transferred to Yarmouth docks where they gave many years' good service.

I have recently been sent a 1933 instruction manual covering the various LNER Sentinel Locos and Railcars. It includes a diagram of the layout of this Y10 double-cabbed loco. (Click the diagram to enlarge it).

General layout of both front and rear cabs

It shows how the front cab regulator lever was connected across the top of the central water tank to the regulator valve itself in the rear cab. Obviously, this loco could not be single-man operated whilst driving from the front as a fireman was still needed by the boiler at the rear.

Various identities have been suggested for Sentinel 7109 when it gets into service; however, a variant with a front mounted cab is one I had not considered until now!

'Ello, 'Ello, LO!

Apologies for pinching this from the SDC Website!

On Saturday 11th Feb 2012, at the AGM of the Sentinel Drivers' Club in Liverpool, Tony Thomas (records officer) proposed and various members of the Goold family seconded me to take over the committee post of Locomotive Officer for both steam and diesel technologies. This I have gladly accepted and hope I can do the post justice.

The post has been held for many years by Martin Hawkins, uncle to Sentinel 7109's boiler inspector Peter Hawkins, a boiler maker in his own right and driver on the West Somerset Railway. So I have quite an act to follow.

To some extent, the task is a blank sheet for me to make of it what I can; the main object being to be the point of contact for anyone with queries about Sentinel locos. Where I don't know an answer, hopefully I can find someone who does!

Tony Thomas has kept records of locomotives still in existence for many years. I hope to make use of his existing information and to keep it up to date using a website, 'blog or such like.

Wish me luck!

100 HP Sentinel Locos (Fry's Type)

I've been asked for information about the Fry's Sentinel loco which was rescued and returned to its original home area in 2010. Avon Valley Railway are doing the restoration work.

As a late addendum to '100HP Pre-war Sentinel Locos' posted in 2011, the following pictures are taken from the 1931 Sentinel catalogue '"Sentinel" Patent Locomotives'. It includes the following details of the Fry's loco type (Click the pictures to enlarge):

The Fry's Loco

100HP Loco as used at Fry's in Keynsham

See page 53!

Old catalogues do come in handy sometimes!

To Inject or not to Inject?

Part of the fun of doing a loco restoration is trying to resolve mysterious features that aren't obvious as to their purpose or function.

Lately, whilst cleaning up and renovating the pair of water tank filter valves, I've been pondering the purpose of a small tube on the left hand side of Sentinel 7109's water tank that is there in some photos but not in others.

Have a look at this:

Sentinel 7109 at Shrewsbury prior to delivery, probably 1927
(Photo courtesy John Hutchings, Industrial Locomotive Society)

Just in front of the cab on the rear filter valve, there is a small tube:

7109 Tube and valve highlighted

But in this later photo, the tube has disappeared:

Missing 7109 Tube
(Photo cropped from C Verrall 1964 original)

Compare these to the similar Radstock Sentinel (7588) which has two tubes to 7109's disappearing one.

Radstock Sentinel 7191 (wks no. 7588) showing its twin tubes
(Photo cropped from R. G. Jarvis original, Richard Dagger collection)

So what was going on, I hear you ask?

Sentinel 7109 was originally supplied with an injector; however, it apparently did not work very well and was soon replaced by a Worthington Simpson type boiler feed pump mounted on the right hand driver's 'window ledge'. Hence the tube was there to feed the injector in the early photo but missing in the later photo.

So if an injector did not work for Sentinel 7109, why was one or more then fitted to the later Radstock Sentinels and left there?

That is the question!

Comments welcome!

Sentinel 7109's Lower Gear Housings

Since July 2011 (now September), I've taken some better photos for this article so here's the new 'enhanced' version!

Three new inspection bolts have been made for the level check holes in the lower gear housings.

Inspection bolt with blind axial hole and linked radial aperture
for oil level checking

The bolt is partly removed to check if oil comes out of the radial aperture

View from above

So why three level check holes and not just one? Simply, it depends on the size of the gear wheel inside. Sentinel offered the ability to change the gear ratio to suit each customer's haulage and speed requirements.

7109 was set up for slow, heavy haulage (I'm guessing here but it will be obvious in due course); hence it will have a large gear in the lower gear case. As a result, it will not need such a deep oil bath as one set up for higher speed with a smaller gear in the same place. So the the check hole actually used will be to suit the expected oil level inside.

Going off-subject for a moment, the Teifi Valley Railway visit on 18th September 2011 revealed an interesting angle on this with the double geared Sentinel 9622 built in 1958. Have a look at the next two photos:

Near side lower gear casing (9622)

Off side lower gear casing (9622)

Note that the drain cock (posh way of doing it) on the near side is on the middle level whereas, on the off side, the drain cock is on the top level. At first, this seems to be a mistake; however, it is a double geared loco with different sized gears in the near and off side casings. Hence a different oil level is needed for each. (It's inevitable that however many photos are taken at the time, something else needs to be illustrated when the time comes. Anyway, hopefully these are just about good enough to illustrate the point).

Also noteworthy in the 9622 photos is that bolts rather than studs/nuts are used to fix the plate in place.

Does anybody know what that big nut-like thing is in the middle of each cover plate? I guess it's a means of draining condensate from the gear case but it was so covered in green slime and it was raining hard that day so I didn't feel much like crawling about underneath and cleaning it up to find out!

A final noteworthy point: in the bottom right of the off side photo can be seen a drive chain. 9622 has double width chains whereas 7109 has single. The double chains would have been used for extra strength as, with double gearing, the drive would be only via the left or right hand chain depending on whether high or low gear was selected. 7109 has one single width chain per engine.

Back to 7109: the new gear housing bottom plates are under construction in preparation for crankcase oil to be added. Hopefully the oil will dampen the unceremonious 'clanking' heard when running on compressed air without a load.

The bottom plate goes here

Crankcase oil is a special type designed for Sentinel steam engines. Its specific characteristic is that water condensate separates out and sinks to the bottom easily for draining off.

Definitely Crankcase oil required!

When fitting 7109's gear case bottom plates, a gasket will be required between the plate and the housing. Hexagonal headed screws will need to be used with fibre washers to hold it in place as some of the holes into the housing are open to the oil contained within; without fibre washers and fixed-head screws, the oil will be able to seep out via the thread in the housing and the thread in the nut and possibly also between the nut and the bottom plate.