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Hornby Rebuilt class 7P “Royal Scot” 4-6-0 46140

“The King’s Royal Rifle Corps”

Review by David Blythman

Train Vehicle Rolling stock Wheel Track

The Prototype

The Original

By 1926 it had become painfully clear to the LMS that it
needed a more powerful locomotive to replace the doubled headed regime
which was then hauling the premier London – Glasgow expresses. As the LNER
had done the year before, the LMS arranged to borrow a Castle class
locomotive from the GWR and once again the Castle proved a more than
competent performer. This settled the design as a 4-6-0. The LMS had hoped
to gain access to working drawings for the Castle but the GWR did not
oblige. The company did get a set of drawings for the SR’s Lord Nelson but
it seems little use was made of them. Such was the rush to get the
locomotives into service that 50 were ordered from North British straight
from the drawing boards at Derby.

These 50 locomotives were built by North British at their
Queen’s Park and Hyde Park works. The first was delivered in July 1927 and
all were in service by the end of the year. Despite some teething problems
a further 20 were built at Derby in 1930.

The Scots remained in the front line of LMS passenger
duties until Stanier’s new pacifics came on line.

The Rebuild

Although the Scots received the new taper boilers as the
original boilers fell due for renewal from the early 1940s onwards, it is
clear from company documents that Stanier had a rebuild in mind as early
as 1934. The original locomotive was too heavy for large parts of the LMS
network including the Midland Division. There was a tendency for coal
consumption to rise sharply between overhauls because the pistons had only
one ring to seal them in the cylinders. As these wore in service, a large
part of the steam went straight past doing no work. The smoke box was
difficult to clean due to its design, resulting in an excessive loss of
“in service” time.

Despite recognising the need for an improvement, this
project was less pressing than the development of the new pacifics and the
smaller 5XP (Jubilee) class locomotives. That is not to say that nothing
was done. The ill fated high pressure locomotive ‘Fury’ was fitted with a
large taper boiler (classified as type 2), renamed “British Legion” and
proved a useful, if ultimately unique engine.

In 1942 two Jubilees, 5735 and 5736 were fitted with a
slightly modified version (type 2A) of the taper boiler fitted to “British
Legion”, modified cylinders and valves, better bogie control and numerous
other refinements. Not only did these two up rated locomotives outperform
their peers, they outperformed the original Scots as well. The
authorisation to rebuild all of the Scots swiftly followed and the
rebuilding process began in 1943 and continued until the last of the class
went through the works in January 1955. The rebuild was every bit as
extensive as that for 5735 and 5736 with little more than the cab
remaining of the original locomotive.

The Tender

When originally built, the Scots were paired with 3,500
gallon Fowler tenders. During 1932 coal rails were added to increase
capacity but from 1936 the tenders were replaced by the new Stanier 4,000
gallon, 9 ton high sided design. These were taken as a straight swap from
Jubilees but unlike the Jubilees, the Scots were generally paired with a
single tender for life.

Vital Statistics (Rebuilt)

Weight: Locomotive 83 tons (~83000kg)

Pressure: 250psi Superheated

Driving Wheels: 6’ 9”

Cylinders: 3

Valve gear: Walschaerts

Tractive Effort: 33,150


Two rebuilt Scots were selected for the BR Interchange
Trial of 1948 in which they turned in remarkable performances in the
express category along side Coronation, A4, Merchant Navy and GW King
locomotives. Such was the success of the rebuild components, the Scots
outperformed the larger Kings much to the chagrin of the GWR. The balance
of power tipped back in the Kings’ favour when they were later fitted with
double chimneys.

One of the Scots’ weak points was their rough riding
particularly when coming up to a major overhaul. When a Scot due for a
service encountered a below par stretch of track it was not unknown for
the footplate crew to grab hold of something solid to steady themselves
against the bucking ride.

A few Scots broke the 100mph mark though not as many or as
frequently as the Kings.

Areas of operation

The rebuilding of the Scots allowed them to operate over a
wider part of the LMS. They were regularly rostered on the following
‘named’ trains – Thames-Clyde Express; The Waverley; The Ulster Express;
The Irish Mail; The Merseyside Express; The Lakes Express. These trains
were worked out of either Euston or St. Pancras. Photos also show Scots at
the head of Liverpool – Newcastle workings, so trips to the ECML were not

Like many other steam locomotives, the Scots were
displaced north westwards by the advent of diesels in the late 1950s. In
the latter days of steam when ‘live’ steamers could turn up almost
anywhere, 46141 was photographed on Eastleigh shed in February 1963.

All major servicing work was carried out at Crewe.


The Scots were withdrawn from service between October 1962
and January 1966.


Two members of the class have been preserved – 6100 “Royal
Scot” and 46115 “Scots Guardsman”. They have both been in running order
but are currently receiving major overhauls. “Royal Scot” is owned by
Bressingham Steam Museum. It is currently being worked on at the London
Mainline Steam Group’s Southall works. 46115 is privately owned and is
believed to be at Carnforth.

The Model

Hornby has produced n models of the Royal Scot class in
this first release

R2628 46102 “Black Watch” BR green; early crest; pristine condition

R2629 46140 “The King’s Royal Rifle Corps” BR green; early crest;
weathered condition

R2630 46146 “The Rifle Brigade” BR green; late crest; pristine condition

R2631 6133 “The Green Howards” LMS 1946 Black; red and straw lining

Each model is available as DCC Ready or DCC fitted.

This review is of R2629 “The King’s Royal Rifle Corps” in
DCC Ready form.

Opening the box

The locomotive comes in one of Hornby’s sleeved boxes
where the sleeve shows the particular model on the front with historical
information relevant to that model on the back. The blue “DCC Ready” flash
is also printed on the sleeve.

Inside the sleeve is a standard model railway box
enclosing a two part polystyrene casing. The two halves of this casing are
held together at each end by clear plastic bands. These are easily removed
to allow the top half of the casing to be removed. The tender can now be
lifted out of the box. The locomotive is still held fast by a pair of L
shaped brackets which have been screwed to the base of the wheel keeper
plate. The long part of the L is a press fit into the bottom half of the
polystyrene casing. A little gentle upward pressure is all that is
required to ease the locomotive away. The next task is to loosen the
keeper plate screws to free the L plates. Until these are removed, the
locomotive cannot be placed on its wheels.

Compared to other locomotive packing methods, removing the
model is particularly easy with this design.

Detail parts

The add on parts consist of locomotive brake rigging;
tender brake rigging; NEM coupler for the front bogie; front footsteps;
front vacuum pipe; dummy screw link coupling; drain cocks

First sight

Train Vehicle Wheel Rolling stock Rolling

The overall impression is of a nice understated model.
This is partly because 46140 is the variat with a “weathered” finish. The
lower part of the model has been lightly sprayed with a dusty colour. The
chief beneficiary appears to be the valve gear. The lining is particularly
neat and unobtrusive.

Having pored over many photographs prior to obtaining this
model, there were few surprises when I looked at it for the first time out
of the box. The usual RTR over large gap between locomotive and tender is
present though with the folded cab doors it is not as obtrusive as it
could be. The height disparity between the cab footsteps and the tender
footsteps is also present on the prototype.

There is no mould line along the centre of the boiler.
Instead there are two faint lines discernible about 6 mm either side of
the centre line. The holes in the brake rod actuators are conspicuous for
some reason but there’s brake rigging in the detail parts bag to fill

The front end looks particularly bare. The front steps and
cylinder drain cocks are both optional and intended for those with the
wider curves which don’t force the leading bogie so far from under the

On the plus side, there is plenty of detail on the
footplate. My personal favourite is the box with multiple copper coloured
pipes coming out of it.

How does it run?

For many people this is the most important attribute of
the model – does it run well?


Hornby state that you need a minimum of radius 2 curves to
run this model. If you fit the front steps and drain cocks the minimum
radius goes up to 25” which is more than many people have room for.

My layout is a mixture of Peco streamline code 100 and
code 75 with electrofrog points, slips and crossings. There were no
problems with derailments and none of my curves posed a problem for the
steps or cylinder drain cocks.

Electrical connections

Like all Hornby’s recent steam models, 46140 has
electrical pickups on all six driving wheels and all six tender wheels as
well. The additional tender pickups turned out to be vital when I was
programming the DCC decoder on the programming track. There was the
occasional hesitation at very low speed indicating some “misses” despite
six points of contact down both sides. I don’t know if this is
attributable to the model or to the decoder. A Hornby A4 which has pickup
on 6 driving wheels and 8 tender wheels and a Lenz gold decoder never

Top speed

With those large 6’ 9” drivers and standard Hornby gearing,
the top speed the model can achieve is far in excess of the prototype.

Low speed

Low speed performance is excellent provided the decoder is
getting power from the track. On my rolling road, the motor would turn
without pause at speed step 1 of 128. At this speed, the movement of the
driving wheels is almost imperceptible.


The model performs well on the level and pulled an 11
coach train including 4 Hornby illuminated Pullmans with ease.

On a 1:50 gradient, there was a little wheel slip when the
last Hornby Gresley of six was on the slope but the model was able to
continue. It was not able to start the train while on the gradient. There
was no wheel slip, just a worrying buzzing noise suggesting that the motor
worm wheel was not engaging. The limit would appear to be about 5 coaches
for 1:50 and less for anything steeper than that.

Fitting the detail parts

The detail parts are fairly easy to fit. I would advise
fitting the locomotive brake rigging starting from the cab end. The front
steps have to be glued in place. Everything else is a secure push fit.
This job is best done after DCC conversion.


In DCC Ready models, the 8 pin NEM socket is located at
the front of the boiler just behind the smokebox. (An important note for
Seuthe customers. The smokebox is entirely enclosed. A lot of surgery is
required if you are going to fit a smoke unit). As I have now converted to
DCC, details of how I fitted a decoder are included at the end of the

Summary of operating characteristics

  • Recommended radius 2 or larger

  • Sealed for life can motor

  • Current pick up from all six driving wheels and all six
    tender wheels

  • Loco / tender connection by standard Hornby pin and hole
    with two circuit link

  • DCC 8 pin socket in boiler

  • No load current consumption (measured): Forwards:160 mA;
    Reverse: 160 mA; Stall Current ~1 Amp.

  • Current consumption (Manufacturer): 200 mA to 400 mA.

Other features

  • Weight:425 grammes

  • Couplings: Front – NEM 362 coupler mount. Tender: Press
    fit to peg.

Third party add ons

If the standard Hornby detail parts such as safety valves
and whistle are not to your liking, companies such as Brassmasters make
turned parts which may suit you better.

Alternative wheels can be had from Markits.

Kadee couplings

This is the biggest disappointment for me on this model.
The tender coupling is a “press fit” to peg design, not the NEM 362 that I
have become used to on Hornby’s A3 and A4 pacific tenders. Conversion is
not going to be a simple job.


Hornby does not yet produce any models with steam sound
and there are no British three cylinder steam sounds on the after market
either. Should such a product appear, the tender is the obvious home for a
sound decoder and loud speaker. There appears to be enough room for one if
the weight is relocated and a judicious amount of surgery is carried out
on the coal bunker.

Train Gas Composite material Brick Engineering

The speaker in this photo is a DCC Supplies bass reflex
model. These are larger than the usual oval speakers.

Product Rectangle Audio equipment Technology Font

How does it measure up to the prototype?

General appearance

Train Wheel Vehicle Rolling stock Mode of transport

I have never seen “the real thing” so my impressions are
based on a lot of black and white photographs, most of which have been
taken from ground level. The model certainly ticks all the right boxes for
Royal Scot features – distinctive smoke deflectors, double chimney, taper
boiler, large driving wheels, running plate mounted sandboxes, footsteps
below the smoke box, Stanier high sided tender.

By coincidence (or else the Hornby designers also own the
book) there is a double page photo of 46140 “in perfect nick” in “The book
of the Royal Scots”. This is large enough to allow me identify the various
parts on the left side of the locomotive. As far as I can tell, apart from
the leading wheel sanding pipe, everything is present and correct. I
haven’t counted the rivets but they look right. Looking at the name plate
you might think that the regimental badge is missing but the photo of
46140 shows that there was no badge. Each of the driving wheels has a
different arrangement of balance weights.

Train Wheel Vehicle Rolling stock Steam engine

I have a particular liking for outside valve gear. All the
major components have been modelled by Hornby and there is very little
“slop” evident as it runs at low speed. The coupling rods are of the
fluted type which is correct for the period represented.


There is a wealth of detail on this model. My particular
favourite are the boxes and associated copper coloured pipe work at the
forward end of the running plate.

Gas Machine tool Auto part Machine Motor vehicle

The shed plate on the front is 9A – Longsight
(Manchester). 46140 was allocated to this shed from June 1954 to September

Train Camera accessory Camera lens Railway Cameras & optics

The cab is yet another highly detailed Hornby production
and yet again I have to rely on an enlarged photo to take in all that is
present. The dials do have faces complete with numbers and a needle
indication. The roof vent can be opened and closed.

Gas Train Engineering Machine Auto part

The tender has a removable coal load which reveals the
shaped bunker underneath. The rear of the tender carries two plates. One
gives the water capacity – 4000 gallons; the other is the build plate –
LMS 9341. I can’t make out the year. 46140 was paired with tender 9341 in
May 1936 and retained it for the rest of its working life.

Other models

Airfix made a model of 46100 Royal Scot in the late 1970s.
In terms of detail and performance it was a considerable improvement on
other British outline models available at the time. Even now it is still a
reasonable looking model. For some, the chimney shape of the Airfix is
better than the Hornby. I don’t have any drawings for the chimney so I
can’t say which is correct. Here’s a photo of the two models head.

Wheel Automotive tire Motor vehicle Tire Train

Train Wheel Vehicle Rolling stock Steam engine


This is another fine model from Hornby. It captures the
essence of the prototype well. It has a wealth of detail above and below
the running plate and is a good runner. The DCC installation is a tight
fit but if you don’t want advanced decoder ‘bells and whistles’, Hornby
also have DCC fitted versions available; just add an X and a few more
pounds. I am in a minority who fit Kadee couplings to their models, so my
disappointment at the tender coupler mounting will not be shared by many.
I look forward to other members of the class being produced in the years
to come. A Holbeck based Scot would soon find a home on my layout.

Fitting a decoder

First the front bogie has to be removed

Black Automotive tire Motor vehicle Gas Automotive wheel system

to gain access to the screw under the smoke box which
secures the boiler to the chassis

Camera accessory Gas Auto part Gun accessory Trigger

Once the screw has been removed, the chassis can be
separated from the body by pulling gently down on the cylinders. The body
is a tight fit and with all that delicate detail is a slightly stressed
moment. The chassis has to clear the front of the footplate before it can
be drawn forward to release the chassis lugs from the backplate.

Motor vehicle Automotive design Automotive exterior Automotive tire Vehicle

Once the body and chassis have been separated you see that
there is not a lot of space for a decoder. A long thin rectangle is more
likely to fit than a thin square.

Automotive tire Motor vehicle Bumper Automotive exterior Automotive wheel system

Neil Wood managed to a fit a Lenz Gold to his Scot. I
don’t know how he found the space. I opted for a Zimo MX620R which is

Passive circuit component Circuit component Hardware programmer Electrical wiring Computer hardware

As you can see, the MX620 is not as long as the splasher.
The chassis completely fills the gap in the bottom of the boiler so
decoder and its wiring have to in the space at the boiler sides and just
in front of the decoder socket.

Hood Automotive tire Automotive lighting Motor vehicle Circuit component

At this stage you should check that the model runs
smoothly. If it doesn’t run well on DC, DCC isn’t going to make it any
better. Now plug in the decoder and check that everything is working. This
took me some time as I was get errors writing CV values. The problem only
went away when I attached the tender. It is important that you do this now
because once you get the body back on, you will not want to repeat the
process. Be very careful when you are testing the decoder at this stage
that none of the live parts come into contact with anything conductive and
short out. If that happens, the decoder will probably be toast. When you
are happy with the decoder operation, it’s time to secure the decoder to
the body and put it all back together again.

The MX620R comes with a sticky pad which you can use to
secure it to the inside of the boiler like this:

Hood Automotive lighting Motor vehicle Bumper Vehicle door

The lead is just long enough to allow the body to lie on
its back alongside the chassis while you plug in the decoder. Now comes
the tricky bit. There are several things you must watch for at all times:

  • The leads to the tender drawbar need to go inside the
    injector pipework.

  • The leads to the decoder must not get trapped between the
    body and the chassis.

  • There are tiny little brackets on the valve gear which
    slop about a lot from side to side. They are supposed to go behind a
    circular bracket under the running plate but they are more likely to flop
    sideways and go the wrong side of this bracket. They are not very strong
    and will get bent if you don’t notice in time.

The body should drop into place without too much pressure. If you are
having to press very hard, then something has got trapped. If it’s not a
decoder wire, it’s probably one of those valve gear brackets.

Links and References

The book of the Royal Scots. A British Railways
Illustrated Special. Published by Irwell Press. ISBN 1-871608-99-6

Great railway photographs by Eric Treacy. Compiled by G.
Freeman Allen. ISBN 0 7537 0872 8

Gresley and Stanier – A Centenary Tribute. John Bellwood
and David Jenkinson. HMSO ISBN 0 11 290253 7

The British 4-6-0 John F Clay. ISBN 450 03239 6.

British Railways Locomotives – 1955. Chris Banks.
Published by OPC. ISBN 0 86093 560 4.

British Railways Locomotives & Locoshed Book 1959.
Published by Ian Allen ISBN 0 7110 0726 8

- October 2007

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