Top Speed of King Class?

[metrobus]

Wasn't it GWR practice to run at Full Regulator basically all the time and adjust the power by use of the reverser. I also remember you had to coast with the regulator partly open to allow steam to the lubricator or something
Edward

[Kariban]

I think that was good practice for everyone since about 1880, Ed :p

[stuart666]

GWR regulators did have intermediate positions, ive certainly seen some records indicating positions such as 75 or 35 percent.

That King dyno run you had was all 100% or 50% or 0% ( aside from starting off, when you're trying not to throw the fire up the chimney ), which matches the regulator valves & makes sure you've never got a partly open regulator - it's effectively two regulators in one, so no partial valve openings. While I'd imagine that was a crew performing their special best, I can't really imagine many situations where you wouldn't either be at one of the two full open positions or coasting. It's surprising how much time you can spend coasting.

There is a set of timings in OS Nocks Stars Castles and Kings that suggest there is more positions than that. It gives timings for King James on the down Cornish Riviera and not only shows reverser positions but also regulator positions. There seems to have been shut, 1/4, 1/2, 3/4 and full. So basically you have a position at each quarter, with the reverser for fine tuning. Almost like notches in the class 47.

Once again, it would be very interesting to set the loco up like this. Presumably many of the other GWR locomotives would have been the same?

[metrobus]

Aren't they just to give an indication of where the regulator is, since you cant say the regulator is at 57% like you can ( roughly ) with the reverser
Edward

[stuart666]

Aren't they just to give an indication of where the regulator is, since you cant say the regulator is at 57% like you can ( roughly ) with the reverser
Edward

But thats the point, why would it be in that position at all unless it was actually working? I accept that you didnt actually have a lock, so you could put it in any position around its axis you like. But if its sitting at half open, or quarter shut, then there must be some utility to it. It has to have more functionality than just open or shut, or thats just where they would have put it.

[windberg]

Beside the top speed of the King am I the only one where the L and K keys for the water pumps do not work?

[kirkheath]

Aren't they just to give an indication of where the regulator is, since you cant say the regulator is at 57% like you can ( roughly ) with the reverser
Edward

But thats the point, why would it be in that position at all unless it was actually working? I accept that you didnt actually have a lock, so you could put it in any position around its axis you like. But if its sitting at half open, or quarter shut, then there must be some utility to it. It has to have more functionality than just open or shut, or thats just where they would have put it.

Having driven a 2884 (38xx) I can tell you that all notches or indications are on the reverser and not regulator. Whether this be a screw reverser that tells you with the gauge next to it, or with freight engines, having the pole reverser which have a number of notches. The only engine I have seen with notches on the regulator was the USA designed S160 which actually also used steam operated reverser and regulator. Not sure if BR standards had notches, I don't remember them having any.

The regulator is free movement from fully closed to fully open. Unofficially there0 are two phrases related to positioning of the regulator: 1st Valve; which is anywhere from fully closed to half power, and 2nd Valve half power to fully open. This because generally, steam engines have two steam chest valves. Fully closed to half open, just allows steam to travel through the first valve, and anything more than 50% power opens the 2nd steam valve. This is why the cylinder beats are alot louder as more steam is passing through the cylinders blocks. It is called the regulator because, it denotes how much steam is allowed to pass through the steam chest valves into the cylinders. Much like accelerators on cars allow the amount of fuel and such to pass through the engine in a car.

Also, as Edward said, particularly with western engines. When coasting, the regulator should always be left open slightly (just off the locking bridge) as GWR engine designs used a lubricator design (I forget how it was powered), either steam or vacuum or different means fed oil to the cylinders and steam chests, I think it was implemented with efficiency in mind. It is rather bad to fully close the regulator as it prevents and oil flow going directly to the steam valves and cylinders. As a result for a long periods of coasting with it fully shut could cause bad problems to motion and eventually wear or seize the motion as it would be metal acting on metal.

On the topic of western engines, if anyone is unfamiliar with the popping or ticking noises you hear between revolutions when the return crank is pulling the piston away from the end of it's travel. This is because they have vacuum pumps connected to the motion which keeps the vacuum in the braking system since GWR use vacuum brakes.

I recently bought a book off Amazon which was titled how a steam engine works , so when I read it properly I can delve even deeper into the technology of these machines. When you think about it, for the time period they were rather technologically advanced on the mechanical side.



I have not drove the King for a while, I have just taken her for a spin and with a load of 12, top speed I could manage on pretty level track was 74.6 mph 100% regulator and 23% cutoff. Something is deffinately not right somewhere. My K & L keys are also broken. but F and R work

[Springer6]

Bear in mind, GWR brakes are off at 25, so if you have anything less than this it may explain why its hard to get any speed out of it.

Yeah 67 is about top with those carriages. If you swap them out with Mk1s you will do rather better. Should be ok on South Devon banks, just keep the steam pressure up and as said, make sure the dampers are full open.

stuart666,

The interesting think here is that you seem to be able to go up to about 30% brake application whilst still maintaining the "running" indication and the full 25 inches of vacuum. You have to create the vacuum first of course, not just by putting the brakes to 0%, but by by putting in the small and possibly the large ejector. However once 25 inches is obtained you seem to be able to maintain it , even with the brakes at up to 30% ( as long as the pop up legend says "running") . I have no idea whether this is realistic or not, perhaps the chap who has some footplate experience on the real King could comment ? Brian Topping in his "Engine Driver's Manual" implies that the GWR vacumm brake only had two positions "On" and "Off", but then he was an LMS man.
Other RW locos including GWR types seem to work best with low "running settings of 5-9%

However , without a high figure of brake application ( at least 23% ) the King does not seem to generate any steam to speak of ( it's probably all going to the ejectors ?) and so it is impossible to generate more steam than you are using. This of course results in falling boiler pressure etc . Result, very poor performance indeed.

I have found that you can get reasonable performance with a high brake setting ( but still "running"), so I'll stick with that for now.

I've noticed that the King is a lot more lively with Mk1s ( blue and grey ones in the other default scenario) so I'll take your advice and swap out the Centenary coaches with choc and cream Mk1's before tackling Dainton Bank.
No passenger view anyway with the Centenary coaches !

[metrobus]

You may aswell ignore what the brake setting on the hud is, its some clever scripting to allow the large ejector to be used. The main one you have to worry about is where the ACTUAL brake handle is

On a side note in real life the Kings class had Large and small ejectors aswell as the Vacuum pump, the small ejector was added because at low speed the vacuum pump is inefficent at maintaining vacuum on a long train ( and short for that matter ). The large ejector is fairly wasteful, and fairly awkward as you keep having to opening and shuting it to release the brakes every 5 or so seconds so the small ejector was added which uses less steam and can be used at low speed until the speed is higher enough for the vacuum pump to takeover. The Brake valve itself on the on GWR engines ( apart from the ones with steam brakes such as 45xx ) only had on and off, off being not allowing any air in, and on allowing air rapidly into the system.
Regards
Edward

[chrisreb]

This very interesting discussion makes me want to get the RSC King out again. Had given up as I could never stop the boiler pressure steadily dropping to prevent any sort of performance. Would not have thought about brake settings to help.

[Kariban]

F5 is probably the most useful view for driving steam, you can keep a decent eye on your usage. After a while you get to know the engine a bit and you can just use the cab, but at first the steam production/usage there is a godsend.

What's also useful is to look up the ideal fire mass in the simulation blueprint and try and keep the firemass at or a little below it.

[rhysicus1989]

Beside the top speed of the King am I the only one where the L and K keys for the water pumps do not work?

No mate, I have the exact same problem, the injector steam valves work but the water feeds to not. I have brought this topic up several times but no response has been had.

[kirkheath]

Again as Edward says that's how it is. The only real GWR engine to have realistic brakes in RW is the 56xx, the brake handle is either on or off, bit like the regulator though you can control how much of the vacuum you bleed into the brakes. bit like, the more you add, the stronger the brakes are applied. In real practice, and as I did when driving the 38' the best technique to stop smoothly was to pump the brakes. Say apply the brakes and let the gauge drop a few psi. and release them again, and so on, until you slow down to desired speed. Passenger comfort is maintained this way. Also as Edward says, the vacuum pump isn't really upto it's job until you reach a speed of about 15-20mph, this is why they are left open when leaving stations on preserved lines. Because, like the 56xx in RW, you will start to lose pressure in the vacuum and the brakes will be applied

I have to say, the king although a beautiful model, isn't that great of an add on in RW. I had much more fun in the 56xx or the DT RLP

[stuart666]

Aren't they just to give an indication of where the regulator is, since you cant say the regulator is at 57% like you can ( roughly ) with the reverser
Edward

But thats the point, why would it be in that position at all unless it was actually working? I accept that you didnt actually have a lock, so you could put it in any position around its axis you like. But if its sitting at half open, or quarter shut, then there must be some utility to it. It has to have more functionality than just open or shut, or thats just where they would have put it.

Having driven a 2884 (38xx) I can tell you that all notches or indications are on the reverser and not regulator. Whether this be a screw reverser that tells you with the gauge next to it, or with freight engines, having the pole reverser which have a number of notches. The only engine I have seen with notches on the regulator was the USA designed S160 which actually also used steam operated reverser and regulator. Not sure if BR standards had notches, I don't remember them having any.

The regulator is free movement from fully closed to fully open. Unofficially there0 are two phrases related to positioning of the regulator: 1st Valve; which is anywhere from fully closed to half power, and 2nd Valve half power to fully open. This because generally, steam engines have two steam chest valves. Fully closed to half open, just allows steam to travel through the first valve, and anything more than 50% power opens the 2nd steam valve. This is why the cylinder beats are alot louder as more steam is passing through the cylinders blocks. It is called the regulator because, it denotes how much steam is allowed to pass through the steam chest valves into the cylinders. Much like accelerators on cars allow the amount of fuel and such to pass through the engine in a car.

Also, as Edward said, particularly with western engines. When coasting, the regulator should always be left open slightly (just off the locking bridge) as GWR engine designs used a lubricator design (I forget how it was powered), either steam or vacuum or different means fed oil to the cylinders and steam chests, I think it was implemented with efficiency in mind. It is rather bad to fully close the regulator as it prevents and oil flow going directly to the steam valves and cylinders. As a result for a long periods of coasting with it fully shut could cause bad problems to motion and eventually wear or seize the motion as it would be metal acting on metal.

On the topic of western engines, if anyone is unfamiliar with the popping or ticking noises you hear between revolutions when the return crank is pulling the piston away from the end of it's travel. This is because they have vacuum pumps connected to the motion which keeps the vacuum in the braking system since GWR use vacuum brakes.

I recently bought a book off Amazon which was titled how a steam engine works , so when I read it properly I can delve even deeper into the technology of these machines. When you think about it, for the time period they were rather technologically advanced on the mechanical side.



I have not drove the King for a while, I have just taken her for a spin and with a load of 12, top speed I could manage on pretty level track was 74.6 mph 100% regulator and 23% cutoff. Something is deffinately not right somewhere. My K & L keys are also broken. but F and R work

Oh agreed, In fact I know that even the screw reversers have a lock, but in service there was sometimes an effort not to use it and to hold it in a position by hand.

The point I was making is that there appeared to be intermediate positions between full open and closed, which seemed to be the debate. What im curious is, how often are those positions used, or generally do they tend to push them to full or quarter port openings where I assume affects would be most noted? I notice in video there is a slow nudging open of the first port. To be honest I cant think of another way of starting a train unless at least in small part there is the ability to slowly open it, otherwise at 75 percent reverser, you would be getting instant wheelspin. Its interesting to note that at pulling away of the King on the Cornish riviera, he stays in first quarter of the regulator for quite a distance to minimise it.


Im interested, how often would people rather see a locomotive modelled like the 56xx, or like the King? I know there was a lot of comment about the cylinder cocks (rightly or wrongly) but were people happy with the rest of how it functioned?

[Kariban]

You don't *have* to use full reverser to start, Stuart but big reverser settings and big regulator openings also mean fierce blast, which tries to take the fire away too - I've not worked out any way of simulating that yet.