Hornby P2

[w4rrn]

Without having to trawl through 23 pages of chatter, are Hornby confirmed to be making a streamlined version in due course, given they've now got the chassis, or is it only entirely sensible speculation so far?

I've not heard any thing to be honest Tony, be nice if they did. Also a 2007 Prince of Wales would be a very popular option too.

[DonnyRailMan]

It would be great if Hornby did have two versions of the P2 the second being the streamlined model.

I know I would have one of each ,but have name changed from Prince of Wales though.

[DonnyRailMan]

Will this new TTS sound system that Hornby are fitting to the C,o,c,k, O North be any better than Hornby`s

original digital sound system.

[Hilux5972]

It has more sounds, I believe 16 in all, but I can't imagine it would be any different quality than the ESU sound they have.

[shunny]

Hornby have said tts is a budget sound range and will try to use actual recordings where available but will use generic sounds where not and as such the P2 will be a generic sound file. They did mention I think in model rail or could have been from rep that steam loco's will have fireman cooking bacon on shovel as one of the sounds so I think we can see the market this is aimed at.

[45568]

that steam loco's will have fireman cooking bacon on shovel as one of the sounds so I think we can see the market this is aimed at.

Low sales in Israel then?

 

Cheers,

Peter C.

[Hroth]

Hornby have said tts is a budget sound range and will try to use actual recordings where available but will use generic sounds where not and as such the P2 will be a generic sound file. They did mention I think in model rail or could have been from rep that steam loco's will have fireman cooking bacon on shovel as one of the sounds so I think we can see the market this is aimed aDepending on what "authentic" soundfiles are available

Depending on what "authentic" soundfiles are available, the sounds from any 3 cylinder Gresley with a Kylchap exhaust will be near enough (discounting the effects of the valvegear).  They'll probably use the "A4" set for "Gadwell" on "Cock", though that may be ultimately derived from "Flying Scotsman".....  I dunno, we'll just have to speculate wildly until someone gets their hands on a specimen!

 

"Frying bacon" does sound a bit "ducking giraffe", something more authentic might be the driver cursing the fireman for not keeping the boiler pressure up to the mark or for making black smoke/blowing off the safety valves within station limits.  Oh well, another missed opportunity!

[melmerby]

Depending on what "authentic" soundfiles are available, the sounds from any 3 cylinder Gresley with a Kylchap exhaust will be near enough (discounting the effects of the valvegear).  They'll probably use the "A4" set for "Gadwell" on "Cock", though that may be ultimately derived from "Flying Scotsman".....  I dunno, we'll just have to speculate wildly until someone gets their hands on a specimen!

 

Won't the rotary gear be a big factor in creating the sound of the "Chuff" of the exhaust, thereby meaning a rather inaccurate sound if a conventional 3 cyl Gresley sound is used?

 

If there will be a future version of the modern re-creation then wouldn't DoG be a better bet as it will have the same gear (British Caprotti) rather than the Lentz gear on the original?

 

Keith

[Hroth]

Won't the rotary gear be a big factor in creating the sound of the "Chuff" of the exhaust, thereby meaning a rather inaccurate sound if a conventional 3 cyl Gresley sound is used?

 

If there will be a future version of the modern re-creation then wouldn't DoG be a better bet as it will have the same gear (British Caprotti) rather than the Lentz gear on the original?

 

Keith

Its going to be (nearly?) a decade before we get to hear an authentic P2 exhaust beat, so the exhaust sound will be more or less inaccurate. Given that there is at least one working Capriotti loco* (Class 5, 73129), perhaps a comparison of that to a conventional class 5 would give an indication of how a conventional A4 exhaust sound might be modified to a better approximation?

 

* ignoring Tornado.....

[melmerby]

Its going to be (nearly?) a decade before we get to hear an authentic P2 exhaust beat, so the exhaust sound will be more or less inaccurate. Given that there is at least one working Capriotti loco* (Class 5, 73129), perhaps a comparison of that to a conventional class 5 would give an indication of how a conventional A4 exhaust sound might be modified to a better approximation?

 

* ignoring Tornado.....

I was suggesting that DoG might be a better bet now for the C o t N model and could be fairly accurate for the new build rather than using a normal 3 cyl loco sound.

 

Keith

[DonnyRailMan]

Hornby have said tts is a budget sound range and will try to use actual recordings where available but will use generic sounds where not and as such the P2 will be a generic sound file. They did mention I think in model rail or could have been from rep that steam loco's will have fireman cooking bacon on shovel as one of the sounds so I think we can see the market this is aimed at.

  Wonder if the fireman would do me a bacon & egg bap LOL.

 

                          D.R.M.

[34theletterbetweenB&D]

I was suggesting that DoG might be a better bet now for the C o t N model and could be fairly accurate for the new build rather than using a normal 3 cyl loco sound.

Probably right, especially when starting, but having heard all of A4s, Tornado and DoG passing; when at speed and well linked up to a short cut off for efficient operation they all sound remarkably alike. Small wonder really, all three cylinder, all with low residual pressure exhaust, coming through a Kylchap ejector system and similar size smokebox volume.

[Hroth]

Quick heads-up

Just got an email from Hattons - if you want a Railroad P2 at their current pre-order price (£67), then act before the 17th, when it increases to £73. If you've already pre-ordered, then as you were... 

[Sam Moss]

well my experience of Caprotti valve gear is LOUD!

[AdamOrmorod]

On a similar topic, how was the inside cylinder on No. 2001 set up? Was it offset by 7 degrees like Gresley's pacifics? Was there a set of Lenz between the frames or were the valve movements derived from the outside valves? Gresley's conjugated valve gear didn't work with poppet valves did it? I ask only because if Cock O' The North's exhaust beat was syncopated, a modified A4 sound file would be appropriate. If the beats were regular, then the Duke of Gloucester.

[PhilH]

well my experience of Caprotti valve gear is LOUD!

 

Not the best example, that thing is priming.....

[gr.king]

(As with those other Gresley locos whose 3 cylinders were abreast, all driving the second coupled axle, the inside cylinder had to be inclined to allow the con-rod to clear the leading coupled axle. If the rotary valve gear was timed correctly for the three cylinders, and why would it not be*, then the exhaust beat would be syncopated just as per the rest of the family.) Correction, 23/3/14 - ignore the foregoing paragraph, it is rubbish! Nimbus is right, in his post below. It's comparable to the cylinders and cranks in a radial engine.

 

There's no need for an extra "set" of Lentz drive gear between the frames as the bevel gears and propellor shaft on one side of the loco only can drive the camshafts for all cylinders.

 

* Exactly what the timing set-up for the Lentz gear was on 2001 may never be known it seems. As revealed at the "P2 Roadshow" today the Lentz company never allowed the LNER to have a set of drawings for its "trade secret" valve gear! Hence the P2SLC are having to search in North America for drawings of the Franklin development of the Lentz system, whose application over there (and elsewhere) included (I believe) long-term successful use of cams with compound curvature of surfaces to give infinitely variable cut-off. Even with the engineering "Achilles Heel" of point contact between cam and follower, when made and set-up properly the Lentz-Franklin type gear was regarded as simpler and more robust than Caprotti gear.

Edited March 23, 2014 by gr.king

[Nimbus]

As with those other Gresley locos whose 3 cylinders were abreast, all driving the second coupled axle, the inside cylinder had to be inclined to allow the con-rod to clear the leading coupled axle. If the rotary valve gear was timed correctly for the three cylinders, and why would it not be*, then the exhaust beat would be syncopated just as per the rest of the family. There's no need for an extra "set" of Lentz drive gear between the frames as the bevel gears and propellor shaft on one side of the loco only can drive the camshafts for all cylinders.

 

The Gresley gear syncopation was accidental, though. If you think about it a bit, the very fact that the middle valve's motion was 'derived' from the two outers means that it could be re-stated as 'dependent' on them, i.e. it and its associated cylinder had no say in the matter of valve event timing, apart from effects of their mechanical loads. Seen from outside, 120deg after the outside cylinder passed TDC, the inner cylinder would arrive at its TDC, even though it is inclined relative to the outer, by virtue of the fact that the inside crank angle is offset in unison with its cylinder.

 

The Nim.

[GNR Dave]

Did anybody see the production example (according to the guy on the stand) on the BRM stand at Ally Pally yesterday. Not sure if it was the Railroad or full spec version. It had full black and white lining (I understood the Railroad version would just have white boiler bands) Unfortunately Hornby were not at the event to confirm one way or the other.(Read into that what you will !) I really hope it was the Railroad version. The light on the stand was not great, and I had my wrong glasses with me (Doh !) but the steam pipe running along the left of the boiler was moulded on, as was the smoke box dart. The handrails seemed to be unconvincing in silver paint, and there was a gap between the smoke box and boiler. This later point may indicate that Hornby intend to do the A4 type smoke box version later as it was obviously an add on part.

 I really hope I'm wrong about the 'short cuts' Hornby seem to have taken, after all it is a RTR P2 and Hornby are to be applauded for tooling up for such a rare locomotive. I have however, cancelled my pre-order and will wait to see what the magazines say in their reviews before deciding whether to get one or not. Hopefully I'm wrong, and the Hornby 'bean counters' have not got to this one.

[Matabiau]

I would expect the P2 to be in the same vein as the recent Duke of Gloucester. The latest images int he Hornby collector magazine appear to show the full spec version given the detailing in the lining and the presence of steam pipes under the pistons. That clearly shows moulded smokebox detail painted silver and gold accordingly. The moulded smokebox dart stands out as it is painted silver, had it been left black it would be less noticeable.

[AdamOrmorod]

The Gresley gear syncopation was accidental, though. If you think about it a bit, the very fact that the middle valve's motion was 'derived' from the two outers means that it could be re-stated as 'dependent' on them, i.e. it and its associated cylinder had no say in the matter of valve event timing, apart from effects of their mechanical loads. Seen from outside, 120deg after the outside cylinder passed TDC, the inner cylinder would arrive at its TDC, even though it is inclined relative to the outer, by virtue of the fact that the inside crank angle is offset in unison with its cylinder.

 

The Nim.

So how did the syncopation occur on Gresley's locos? Wasn't the inside cylinder beat slightly late, caused by its inclination and offset crank? My understanding of Gresley's 3-cylinder layout is shaken.

[gr.king]

As Nimbus has pointed out above, resulting in "the penny dropping" for me at last, the piston movements in the three cylinder engine would actually be dead-on the intended 120 degree distributions. The Gresley-Holcroft valve gear, if working perfectly with no effects of slop in joints, no differential thermal expansion of parts, and no flexing of levers that ought to have remained straight, would also be dead-on for the middle cylinder's derived valve actions. In reality of course there was slop, there was thermal expansion, and there was flexing of levers, so the movement of the middle valves would tend to lag behind phase and vary between insufficient movement in some phases of action followed by overshoot movement at other times. Indicator diagrams from trials confirmed this, with power development being out of balance in the three cylinders in different ways at different speeds, with discrepancies even appearing between power attributable to the forward and reverse strokes in the middle cylinder especially. With different amounts of steam being admitted to the middle cylinder compared to the other two, and its exhaust valve operations also being "off", the pitch, the timimg and the duration of its exhaust beats would be odd.

[Nimbus]

The Gresley-Holcroft valve gear, if working perfectly with no effects of slop in joints, no differential thermal expansion of parts, and no flexing of levers that ought to have remained straight, would also be dead-on for the middle cylinder's derived valve actions. In reality of course there was slop, there was thermal expansion, and there was flexing of levers, so the movement of the middle valves would tend to lag behind phase and vary between insufficient movement in some phases of action followed by overshoot movement at other times. 

 

I often wonder what a dose of modern computer-aided analysis might do for the performance of a refined implementation, in a new-build Gresley-style loco!

 

The B17 and D49 were free of the expansion error introduced by the outside valve spindles, since the conjugated gear was able to be placed behind the cylinders on those designs. Can anyone here remember hearing them working as hard as, say, a V2, and whether they sounded more regular?

 

The Nim.

[Colin_McLeod]

So long as mine sounds like a modern can motor, and not an X04 or pancake motor then I'll be happy.  LOL

[gr.king]

Today, ehattons.com still shows the nice version of the P2 due in "on or after 7th July", the playtime (or modifier's) version allegedly being due as soon as "on or after 28th April".

 

Do any of this site's users have sufficient hard information to give any reliable indication of whether we might really get the basic model as soon as early May - assuming the ship doesn't emulate recent events and "vanish" in the Indian Ocean of course?