# The British Invasion



## Charles (Jan 2, 2008)

TRS is presently working on 4 British locomotives:

Aster A3 kit
Aster A3 repairs
Bowande (Wuhu) A4 repairs
Aster Duchess repairs


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## David Leech (Dec 9, 2008)

Well, Charles,
When I click on "Aster A3 repairs", it looks awfully like a blue Duchess of Atholl!!
All the best,
David Leech, Delta, Canada


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## Charles (Jan 2, 2008)

David
Thanks for the note on the link


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## steamtom1 (Jan 2, 2008)

What kind of repairs are you doing on the A3?


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## boilingwater (Jan 27, 2010)

Charles,

I have interest in your Duchess fixes...what are you rehabbing there?

My Duchess is in a similar place right now..the steam line was replaced among other fixes. That's a bit of pain on that engine since you have to fish it up the length of the engine an take off the backend to get it past the firebox and up to the fitting. Mine also has a Weltyk whistle in the way so it's been crowed in that cab. In fact, I had to take the site glass off to navigate safely in there for that oil/steam line attachment. 

The axle pump has been expanded per Chuck Morton and the timing needs a check. I've received a bit of help on that from John Allman. I was going to send that one to you but perhaps the BR03 will go to you later this month to change these up a bit...


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## Charles (Jan 2, 2008)

We will list the work being done. Off to test two of the locomotive to check the progress and help the "fix" is in!

BTW- add to the list: Aster Rebuilt Merchant Navy kit build.


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## rbednarik (Jan 2, 2008)

boilingwater said:


> Charles,
> 
> I have interest in your Duchess fixes...what are you rehabbing there?



Sam,

Below is a summary of what was diagnosed and corrected on the Duchess: 



On this engine, the valve spindle for the outside valves should seat hard up against the rocker arm pivot pin bushing on the outer valve guide connection. This engine had the spindles back off that and created about 1mm of lost motion in that area. Combine that with the inner valve rods coming loose on the strengthening extension (in the middle), causing more lost motion, and the connection cheeks to the rocker arms were also loose on the rods. All this lead up to 1.5mm lost motion and not equally between inside and outside valves! Timing was a nightmare the first attempt so the whole lot was taken down and rebuilt to save headache. 
All that rebuilt properly and the only lost motion was now back at the expansion link at the die block and minimal enough that it makes no difference in the timing. The engine is now square and notches up well.
You all probably already know this, but it is most important to make sure the valve gear is square (return crank set at correct angle, rods parallel with one another in appropriate positions of the stroke) before attempting to time the valves. 
Once that is set, then set the valves to open each port equally, if not opening fully (or over throwing) on both inside and out, then adjust the return crank to give more (or less) throw.
 
When reassembling the smokebox piping the first time, the flange 
connection for the superheater promptly fell off of one superheater element and with not so much coaxing the second one fell away shortly after. You can see this in a few of the photos posted in the Duchess album.
The brazing failed on both connections so that was one source of loosing power and steam. Re-brazed them and all is good there, reassembled the steam piping with copper crush washers throughout all the banjo fittings to ensure a good seal.
 
The axle pump is the same as the A3 which works fine in stock form (easily fills the boiler at all speeds while just below pop off pressure) and essentially the engines have the same boiler and steam consumption rates so it was time to figure out what the difference was between the pumps.
First thing was to eliminate the known restriction in the connection between engine and tender with a new 2.5mm bore connector. However this did not solve the problem, so on to the next step.

I looked at the A3 and saw a change that was minor between the pump assemblies but seems to be the culprit behind the duchess pump not keeping up. The A3 pump uses (+/-)0.25mm fiber washers on top and bottom of the banjo fittings to the pump, which increased the lift of the valve ball by some 0.50mm. I did not measure the stock duchess valve clearance but since the pump and all other components are the same it is assumed that the lift was short by 0.50mm.
The stock pump keeps up just fine with the engine demand (I ran with the bypass closed until it just started carrying water over into the safety valves), filling it up from 1/4 glass to full in 10 minutes at 60smph, so this fix seems to do the same as the larger pump from Chuck Morton. Although, it is good to have the larger ram as it gives better peace of mind in the long run.
For those struggling with the stock pump (applies to modified pumps as well), checking the amount of lift the ball has is correct from the seat to the limiter should be addressed to be sure you are getting the most out of the pump.
 
The throttle valve was very difficult to use on this particular engine. This was surprising seeing as how how the A3 has such a nice and controllable throttle so i wondered how the Duchess could be so bad since they are the same design throttle. This engine required 3 full turns before any response was seen and then it would take off like a scalded cat within 1/8 a turn more of that.
I took an A3 throttle needle out and saw immediately what the issue was. The inner stepped portion on this particular throttle needle was way too big in diameter and was lacking a taper like the A3 needle had. A quick re-profiling on the lathe and the throttle is now responsive but controllable through a 1/2 turn from closed range, so that when you turn the throttle 1/2 turn to closed the engine actually stops.
*Your mileage may vary, but I prefer to be able to control an engine's (realistic) full power range within 3/4 a turn from closed as a rule, helps you get the throttle shut quickly in case of emergencies.*
 
 
 In an effort to reduce excessive blowing off when running with 12 coaches on, I enlarged the blast nozzles to 1.5mm from the original 1.2mm.
This is in line with calculations of the appropriate 3mm nozzle size for a single stack and 4 11mm cylinders divided in half since the duchess has twin stacks. This is using the 1/7 the cylinder diameter rule for exhaust nozzles.

The final result was very encouraging, as the reduction in wasted steam was notable as was the control of the engine due to the reduced back pressure. Albeit this is a slight change so there may not be much notable difference in increasing the overall blast nozzle area by 0.5mm (0.25mm each stack), but it achieved reductions and economies without sacrificing drafting.



Sorry for the wall of text, but that is what was found. Final proof of the pudding can be seen by clicking the link below. 



Aster BR Duchess On Test


This is before the exhaust enlargement so lots of wasted steam. 



Aster A3 work to be reviewed next.


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## Steve Shyvers (Jan 2, 2008)

Ryan,

Wall of text much appreciated. Thank you.

Steve Shyvers


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## StackTalk (May 16, 2014)

Ryan,

I am making a few assumptions here, one of which is that the Duchess is very similar to the Castle - as far as the "inside" mechanicals go.

The second assumption is that the first item you described repairing is the outside cylinder valve operating rocker arm and fulcrum assembly.

The third assumption is that Sam and others may be interested in seeing what we are talking about?

If any of the assumptions prove to be incorrect, I will delete this post after reading your further comments.

I have about ten hours of run-time on my Castle at this point and hopefully, it will not have to come apart again anytime soon, but I too found the fulcrum pin/rocker arm a point of vulnerability and from the reading I have done, this was true of the various prototypes as well.

In my case, I experienced a couple or related failure modalities that were easy to repair once understood.













Pictured here:










and . . .










When a single fulcrum pin itself loosens, the result is worse than one may expect. 

Not only does the timing go off on the outside cylinder associated with the rocker arm, but the fulcrum pin itself binds the entire chassis as it tends to be forced upward against the inside taper of the rocker arm and because it is a mildly tapered pin, the binding is a bit like a Morse taper - for those who know what that implies!

If the lubrication is insufficient on the pin, a lot of lateral force is exerted in such a way as it may loosen the two screws on the support bracket itself (below the pin,) and then the bracket will rock back and forth.

In either failure modality, before the loco slows to a crawl or a halt, one will hear the change in exhaust note as the one outside cylinder fails.

The insidious part about just the pin loosening and being forced up - is that you may not be able to see it and the chassis will continue to roll OK when not under power.

Finally, I am assuming that this discussion applies equally to the King, the Castle, the Duchess and any other Aster four cylinder loco that has only two inside sets of Walschaerts gear 'tween the frames.

Shall we say this failure provided a good learning experience? You bet.

I learned that, if one applies thread-locker after the parts are well lubricated, don't expect much of anything to be locked. I eventually washed the pins in acetone and after they were well dry, I lubed up the pins carefully getting nothing on the threads and then re-locked and all was well.

Lubrication?

Looking at the images you may come to the same conclusion that I came to . . .

It is extremely important to lubricate the fulcrum pins, and . . .
It is nearly impossible to get lubricant on those pins!

How did I reconcile the contradiction?

I ended up preparing a paste of lithium grease and graphite and I coated the pins before reassembly, again being careful to keep the lube away from the thread-locker.

Dave Stick recommends placing back-up nuts under the pins, which is also a good idea.

Cheers,

Joe


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## rbednarik (Jan 2, 2008)

StackTalk said:


> Ryan,
> 
> I am making a few assumptions here, one of which is that the Duchess is very similar to the Castle - as far as the "inside" mechanicals go.
> 
> ...



Joe,

Not quite the same between the engines. The basics of a divided 4 cylinder drive are the same, but the ways that the valves are driven are different. The Castle follows GWR practice with inside valve gear driving outside rockers through extended valve rod tails. The Duchess uses the LMS style combined valve yoke and rocker drive with outside walschaert gear driving it. 

The below diagram should make things more clear. 








Areas circled in Red are where the lost motion was greatest. 

The arrows point to the source of lost motion, the 1-6 valve rod (not labelled) must be screwed tight against part 4-36 in order to prevent the drive from being too loose once the whole assembly is connected. 

The connection of parts 4-34 and 4-33 with the bolt 4-30 is fine, no lost motion and unlike the castle is a threaded shoulder bolt instead of a taper pin pulled tight by a lock nut.

The other area of lost motion is as seen below (again circled in red with arrows)










This is where the inner valve rods connect to the 4-24 strengthened rocker push rods. 
The valve rods were not steated firmly into the 4-24 pushrods and the whole lot was able to flex up and down causing quite a bit of variance in the valve throw!

The castle information is good to know and useful for all, a locking nut would solve the problem (or renewed thread lock), although a washer would not go amiss to prevent the taper pin from drawing itself loose in the hole as it gives the whole assembly a second bearing point should the pin want to twist. 

I would imagine the pin is stainless or steel of some sort so it will certainly wear down versus the brass rocker arm casting and this will diminish the want to draw itself loose. However, this will take many tens of hours running and very lax maintenance procedures to accomplish! A pinhole in the rocker arm casting would be beneficial as well to allow oil or grease to be pushed into the bearing surface


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## StackTalk (May 16, 2014)

Ryan,

Thank you. 

I hope my post did not put you through too much trouble as I see that it may have had the unintended effect of putting you "on the spot."

I must say that, the more I see of additional Aster builds, the more I appreciate just how much fidelity Aster strives for in replicating, in so far as is practical, the design of the full-size prototype.

I should have looked at a photo of a Duchess and I would have seen straight away that the gear is on the outside on the LMS design and on the inside on the GWR design. From pictures I have studied, I can see the King and the Castle are nearly identical in regards to valve gear operating components.

The fulcrum or pivot point in ether design, with its reciprocating motion, can be a source of trouble.

Having all those moving bits on the inside results in quite a lot of work when just one screw or one pin works its way loose in an inaccessible area.

If I ever get around to doing that "What I learned while building a Castle" thread I will talk about what happens when what I call the "WTF screw" loosens up. 

Spoiler alert . . .

There are a couple of very small screws that, should they loosen, require a complete disassembly right down to removing the outside cylinders. I have only done that far the one time, but once was enough.

Cheers,

Joe


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## rbednarik (Jan 2, 2008)

Joe,

Your post brought about that it was good to give some visual for those who got lost in the wall of text I posted. 

Hopefully all is becoming more clear to those interested, but I am not about to tear it down to take more photos of what was repaired!


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## StackTalk (May 16, 2014)

I do hope no one would expect anyone to take a loco apart just for photos! 

* * *

I took quite a few of the Castle as I was building it though I haven't posted more than a few.

I took more snapshots of the K4s during the refurbishment than I put up as well, but not as many as Charles likes to take. 

At the moment I am building a BR 9F "Evening Star" that I purchased from Doug Hill this past May and I am taking photos, but not at every stage. For example, I did not make a video of the chassis air test this time around, though it passed. I am photographing what I consider to be the interesting stuff like the piston valves and the draincock mechanicals, faux lubricator linkage, etc. I don't want to highjack your thread and move it in another direction than was intended. 

Like others here, I enjoy seeing the work that you and the TRS gang are doing.

I will eventually start a thread for the 9F.

So . . .

Carry on!

Cheers,

Joe


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## boilingwater (Jan 27, 2010)

Ryan,

Thanks for your detailed explanation for what you've found on the Duchess. I've been travelling so I hadn't gotten back to this thread.

The timing on this engine does seem to be a bit of headache post build. There appears to be some slop in the valve gear as you've found and that it seems to cause problems on some of these engines. I'm still hung there for the time being and will get back to trying to get this right. John Allman has been helpful there.

I haven't checked the superheater tubes but I will for cracks,etc.and copper washers.

Interesting find on the axle pump...good note for all other owners to investigate. Wayne?

I hadn't noticed a throttle issue (other than the lack of length) I don't recall seeing any issues with Wayne's Duchess there either...but if you could provide a bit more detail on the change you did, I'm willing to give it a try.

The blower nozzle enlargement was one I received from one of our UK brothers but I had not done. I'm glad to hear that change seems to check out.

This discussion has been extremely helpful since I didn't build this engine.

Joe--I have an Evening Star as well that I didn't build so I'm all ears on a new thread from you on that one....

Let's hope I can post a successfully running Duchess sometime in the near future...

Sam


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## Charles (Jan 2, 2008)

Progress on the Aster A3 kit build:

Aster A3


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## David Leech (Dec 9, 2008)

boilingwater said:


> Ryan,
> 
> 
> I hadn't noticed a throttle issue (other than the lack of length) I don't recall seeing any issues with Wayne's Duchess there either...but if you could provide a bit more detail on the change you did, I'm willing to give it a try.
> ...


Sam,
I don't know which Duchess that you have, but the BLUE Duchess throttle is different to the RED Duchess throttle.
Aster were offering an exchange for those who don't like the BLUE one.
Cheers,
David Leech, Delta, Canada


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## boilingwater (Jan 27, 2010)

Thanks David.

I have the red version...very strange that they would change the throttle design there.....

Sam


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## rbednarik (Jan 2, 2008)

boilingwater said:


> Ryan,
> 
> Thanks for your detailed explanation for what you've found on the Duchess. I've been travelling so I hadn't gotten back to this thread.
> 
> ...



Sam, 

+Copper washers: These are an addition that I made versus the OEM spec of just sealant. Useful if you are dealing with high heat and pressure joints you have to take apart often. These are 5mm ID copper crush available from Jason at the Train Dept and made by Regner. If you are sticking with the sealant route I would recommend Permatex ultra black/ultra copper or Hylomar Blue (available from Grainger)

+ Axle pump: There should be about 0.035" of lift of the valve ball (I ended up just below 0.040, as I only had 0.5mm washers on hand) from the seat on the delivery side, although more is not necessarily a bad thing just so long as it is not more than say 0.040" (1mm)

+Nozzle sizing: I should point it out for the sake of the record that it was the *Exhaust* nozzles, not the Blower that was enlarged to nominally 1.5mm (actual 1.46mm, +/-.025mm on my dial caliper). The blower nozzles should be no bigger than 0.6-0.9mm. But that is what you meant, of course! 

+Throttle: I was unaware of the exchange from Aster for the BLUE throttle, but rather than wait for the parts I modified the taper to match the one on the LNER A3 I have in the shop, since the valves are the same. Not having a RED Duchess here I assume the taper is probably already OK and is exactly what I did to this one.

Best of luck on the work. Timing takes a lot of time to get right, but once you have it set the engine really has more power than it ever can use.


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## David Leech (Dec 9, 2008)

Sam,
I don't know, but I wonder if it was just a mistake in making the parts!
Maybe someone set up the cnc machine incorrectly?
At one point there was a photo of the two side by side so that you can see the difference of the tips, but can't remember where I saw it!
Regards,
David Leech, Delta, Canada


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## David Leech (Dec 9, 2008)

Sam and Ryan,
Just found the photo that was sent to me, and I think originated from Hans, but I could be wrong.
Cheers,
David


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## rbednarik (Jan 2, 2008)

David,

Interesting, I see that not only is the stepped portion larger in diameter, but the taper behind it is different to the two engines with the Atholl having a more blunt angle. 

Will take a photo of the modified one here for comparison's sake. 

Most likely it was a machining error on the batch, but I would bet (pure speculation here) that the 2.4mm is awfully close to the ID of the hole that it seats into (probably 2.5mm or just over) and that is why the Atholl throttle did not work unless you unscrewed it very far out, there simply was not enough steam flow.

The Sutherland throttle looks like the A3 and should do since they are the same design!


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## boilingwater (Jan 27, 2010)

David,
Thanks..that certainly explains where Ryan and I were not seeing the same things on the "same" engine!

Ryan,

Sounds right. It is interesting but a puzzling error for entire batch/run. One would think that such a mistake would have been discovered in operational tests. Clearly, Hans or someone else discovered the mistake after production. It makes me wonder what subtle changes exists between models like the Garratt. I suppose as long as they no not effect the running characteristics then perhaps not a big deal but good for the Aster trivia historian out there.....

Sam


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## rbednarik (Jan 2, 2008)

boilingwater said:


> David,
> It makes me wonder what subtle changes exists between models like the Garratt. I suppose as long as they no not effect the running characteristics then perhaps not a big deal but good for the Aster trivia historian out there.....
> 
> Sam


Sam,

I have quite a list already, but will need to look closely at a first run Garratt. Fundamental mechanics are mostly all the same, but choices of materials are different for some items. 
For example: 
-There are cast iron wheels with steel tires, non insulated on the 2009 production. 
-This is versus the cast stainless wheels with stainless steel, insulated tires on the 1994 production. 

I need to check and see if the 2009 production uses cast (phosphor bronze) or machined (brass) cylinders. I would imagine the 1994 engine used the old Phosphor bronze "W" cylinders that were common on the majority of Aster models since the Schools, differing really only in bore size, valve passage layout and bolt patterns for the heads.

Anyways, back on topic. Here is the photo I promised of the modified throttle, with an A3 throttle needle in for reference.


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## John Allman (Jan 2, 2008)

Ryan - there is no mistake on the throttle. The design was made that way to the specifications that the British end user preferred. The taper allowed very fine adjustment of the throttle at running speeds. The difference is you had to open the throttle more that one turn. 
That was the point, it allows fine tuning. With the system as you are use to it, 1/4 turn is full open.

In any event, glad to hear that you got it running. The Duchess is very challenging to tune, but one of the best there is when you get it right.

Hope to see you, and my BB, in a few weeks.

John


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## rbednarik (Jan 2, 2008)

John Allman said:


> Ryan - there is no mistake on the throttle. The design was made that way to the specifications that the British end user preferred. The taper allowed very fine adjustment of the throttle at running speeds. The difference is you had to open the throttle more that one turn.
> That was the point, it allows fine tuning. With the system as you are use to it, 1/4 turn is full open.
> 
> In any event, glad to hear that you got it running. The Duchess is very challenging to tune, but one of the best there is when you get it right.
> ...


John, 

The inner taper was 2.45mm on this one originally and was not tapered at all (straight), so there was a restriction until you had unscrewed the throttle to the point where you had pulled the inner taper (or lack thereof) out of the seat.

Again, for safety reasons having the control range within 1 turn from seated is beneficial in case you need to get the engine shut down quickly. As it was it took nearly 3, difficult to stop the train timely when you are fiddling with the throttle. 

Even once past the high end "fine" control the cylinders were wiredrawing the steam through the restriction of the "taper" and the locomotive still moving at a pretty good clip.

Just my opinion, but please note there is no lack of control with the modified taper. As modified now there is complete control within 1/2 turn and it is very linear. Why you need more than 1/2- 1 full rotation for control is beyond me, especially if you have to constantly wind it out to get any reaction from the locomotive.

To each his own, but I do not recall hearing any big complaints of the original Duchess throttle being overly sensitive or coarse.


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## boilingwater (Jan 27, 2010)

john,

i understand that this may have been a planned modification not an error but i tend to agree with Ryan's reasoning on the operational benefits. If you want to radio control this engine, Ryan's modification also makes that easier.

How much variance on the outside cylinders timing makes a difference in this engine especially given the operation of the inside cylinders? The delta on mine looks very small between the two sides in neutral with the cranks set properly. I'll see if I can make the small correction there and then go to inside. I'll also look at the two slop areas Ryan pointed out...then I'll test and see what I see....

Thanks to John and Ryan on their help here. I'd be curious what our British experts have seen on their Duchesses given their operational experience. The blast pipe mod was interesting and appreciated. The potential superheater cracks/breaks also sounds worthy of getting feedback regarding anyone else seeing that.

Sam


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## Charles (Jan 2, 2008)

*The British lineup*

Here is a photo of the steam parade of the British invasion

British invasion


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## David Leech (Dec 9, 2008)

Looks impressive Charles.
Cunard White Star - I wonder why the owner chose that name?
Maybe his/her favourite liner company?
All the best,
David Leech, Delta, Canada


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## Charles (Jan 2, 2008)

Maybe it should have been the Canadian Pacific or United States Lines.....for those who might not get David's point of guided inquiry set forth to educate:

The 'Merchant Navies' represented a publicity success for the Southern Railway in highlighting the names of Merchant Navy shipping lines that used Southampton Docks, which were served by the Southern Railway. They also constituted a roving memorial to the seamen who fought at sea during the Second World War to keep Britain supplied with food, fuel and other goods.


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## Chris Scott (Jan 2, 2008)

*Merchant Navy (United Kingdom)*
From Wikipedia, the free encyclopedia
*http://en.wikipedia.org/wiki/Merchant_Navy_(United_Kingdom)*

For the steam locomotives, see SR Merchant Navy class (see below)
From Wikipedia, the free encyclopedia
*http://en.wikipedia.org/wiki/SR_Merchant_Navy_class*

The Merchant Navy is the maritime register of the United Kingdom, and describes the seagoing commercial interests of UK-registered ships and their crews. Merchant Navy vessels fly the Red Ensign and are regulated by the Maritime and Coastguard Agency (MCA). King George V bestowed the title of "Merchant Navy" on the British merchant shipping fleets following their service in the First World War; a number of other nations have since adopted the title.

The Merchant Navy has been in existence for a significant period in British history, owing much of its growth to British imperial expansion. As an entity in itself it can be dated back to the 17th century, where an attempt was made to register all seafarers as a source of labour for the Royal Navy in times of conflict.[1] That registration of merchant seafarers failed, and it was not successfully implemented until 1835. The merchant fleet grew over successive years to become the world's foremost merchant fleet, benefiting considerably from trade with British possessions in India and the Far East. The lucrative trade in sugar, spices and tea (carried by ships such as the Cutty Sark) helped to solidify this dominance in the 19th century.

In the First and Second World Wars, the Merchant Service suffered heavy losses from German U-boat attacks. A policy of unrestricted warfare meant that merchant seafarers were also at risk of attack from enemy ships. The tonnage lost to U-boats in the First World War was around 7,759,090 tons,[2] and around 14,661 merchant seafarers were killed. In honour of the sacrifice made by merchant seafarers in the First World War, George V granted the title "Merchant Navy" to the service.


*SR Merchant Navy class Locomotives*
From Wikipedia, the free encyclopedia
*http://en.wikipedia.org/wiki/SR_Merchant_Navy_class*

The SR Merchant Navy class (originally known as the 21C1 class, and later informally known as Bulleid Pacifics, Spam Cans or Packets), is a class of air-smoothed 4-6-2 Pacific steam locomotives designed for the Southern Railway of the United Kingdom by Oliver Bulleid. The Pacific design was chosen in preference to several others proposed by Bulleid. The first members of the class were constructed during the Second World War, and the last of the 30 locomotives in 1949.

Incorporating a number of new developments in British steam locomotive technology, the design of the Merchant Navy class was among the first to use welding in the construction process; this enabled easier fabrication of components during the austerity of the war and post-war economies.[2] The locomotives featured thermic syphons and Bulleid's innovative, but controversial, chain-driven valve gear.[3] The class members were named after the Merchant Navy shipping lines involved in the Battle of the Atlantic, and latterly those which used Southampton Docks, a publicity masterstroke by the Southern Railway, which operated Southampton Docks during the period.[4]

Due to problems with some of the more novel features of Bulleid's design, all members of the class were rebuilt by British Railways during the late 1950s, losing their air-smoothed casings in the process. The Merchant Navy class operated until the end of Southern steam in July 1967. A third of the class has survived and can be seen on heritage railways throughout Great Britain.


The complete history of the Merchant Nave Class Locomotives makes for great reading.
*http://en.wikipedia.org/wiki/SR_Merchant_Navy_class*
From Wikipedia, the free encyclopedia


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