2001 model
One of several P2 models on display at the roadshow

Being based in the capital, New Build Steam doesn’t often get the opportunity to attend events relating to the many exciting projects taking place across the country, but today proved an exception as the P2 Steam Locomotive Company came to town for the first two of its roadshows to drum up awareness and, of course, funds for 2007 Prince of Wales.

The event consisted of a series of engaging and informative presentations, and New Build Steam certainly recommends getting along to the future roadshows if you can. This post summarises key points from the presentations.

Building 2007 Prince of Wales
The broad schedule for construction was set out, highlights of which include the following.

  • design work: 2013-16
  • frame erection: June 2014, with construction work “in earnest” starting in July
  • first wheels cast: December 2014
  • boiler: 2017
  • trials and testing: 2020

Additionally, it was noted that the smokebox may be completed earlier than it is technically needed; the locomotive’s “face” is valuable for publicity purposes, as was found with Tornado (and as the Patriot group is currently finding with 45551 The Unknown Warrior, one might add).

Such rapid progress, relative to most new builds, is of course dependent on funding being available. Chairman Mark Allatt emphasised the strategy of ensuring a flying start for the P2: it took 4 years to raise the first £100K for the A1, whereas for the P2 it took four weeks thanks to the Founder Club. Indeed, the fact that Tornado’s completion took 14 years was largely down to cashflow; in total, £4million has been raised over the years towards the A1 and its support coach, so the target of £5million and completion in seven years for the P2 is demanding but realistic. Allatt also provided an interesting comparison point: £7million was raised by the ‘Vulcan to the Sky‘ campaign to restore a Vulcan bomber.

Covenant forms
Covenant forms and the official information leaflet

In terms of fundraising detail, the covenant offer for the P2 – for a monthly donation of £10 – was launched at the first of the day’s roadshows, with former A1 Trust chairman David Champion ceremonially signing up as the first covenantor.The Founders Club will remain open to new members until the frames are laid, and the dedicated donation scheme (ie ‘sponsor a component’) launches in October. It was also stated that the collaboration with Hornby is such that all Hornby P2 models will generate a donation to the Trust – not just models of 2007, and not just those sold by the Trust (the timing of the model of 2007 is to be confirmed, but there will be one). A meeting is also due to be held with the Heritage Lottery Fund in the next few weeks, as HLF representatives were reportedly embarrassed on visiting Tornado to be informed that, contrary to their assumptions, the Fund had not contributed a penny to the locomotive (a story whose telling ends with the words “now get out of our cab!” – New Build Steam would be interested to know just how apocryphal that is…).

Other specifics relating to methods of design and construction were also given. For instance, the design work is being done in 3D CAD rather than 2D as with Tornado, which caused some delay to the A1’s build at later stages, as details like cabling and pipe runs could not easily be addressed through it.

Furthermore, it was politely pointed out that poly patterns are not the innovation they might have been reported as recently, as they were used in the construction of Tornado in the 1990s, and will be again used on the P2. Existing (non-poly) patterns for components common with the A1 are being taken from storage and some are already at or en route to foundries.

An improved Gresley P2
Some emphasis was placed on the Trust’s mission statement (italics by NBS): “To develop, build and operate an improved Gresley class P2 Mikado steam locomotive for mainline and preserved railway use.” All six members of the class carried new developments and idiosyncracies, so there is no wholly standard design for a P2. Indeed, the design was not fully developed, as first the A4s drew Gresley’s attention away, and latterly war intervened. But for those things, it is hard to believe that the P2s would not have been refined further, for instance by remedying the known issues with the pony truck as was done with the V2s. The construction of 2007 is therefore being seen in terms of an opportunity to provide some of the development that should have occurred in the 1930s and 40s – though it is primarily a construction project, and will not attempt to re-engineer the design unless there are clear reasons to do so, related either to performance, manufacturing or modern regulatory requirements.

Nonetheless, it must be faced that the P2s did have a known issue with derailments relating to the pony truck, and arguably one with track spreading. However, any such incidents occurred at low speed, in yards with typically low quality permanent way – in the case of Scottish yards, normally required to take nothing heavier than a 4-4-0 or Atlantic. So while it is vitally important to show that such problems would not arise with a P2 being operated on the modern railway, the problems also needs to be fully understood and put in perspective – a challenge with effectively no data or other technical evidence to prove the design’s suitability, unlike with the better-documented A1s.

The work to model the P2 in VAMPIRE(R) software is therefore vitally important, and it has shown that with the pony truck modified along V2 lines, a P2 can be produced with a ride quality at least as good as Tornado’s, and without posing a significant risk of the sorts of derailments seen in the class’s early days. Delta Rail is currently undertaking the final phase of this work, in between its commitments for clients in the USA and China; the P2 group were quick to pay tribute to the company as a British success story on the global stage.

The P2’s crank axle was also known to be a problem area, to at least a modest extent. Crank axle technology in fact advanced significantly during the war, and with today’s understanding of it the shortcomings of the original design, such as they were, are readily apparent. The design fitted to the A1s less than a decade and a half after the first P2 was outshopped was shown to have a 60% better performance in terms of fatigue than its 1930s predecessor, and further improvement on this is entirely feasible. Accordingly, the design of crank axle used on Tornado will be reproduced on Prince of Wales.

Tornado headlamp
One of Tornado’s LED headlamps, this example also having been used on Bittern’s 90mph runs in 2013

Operation on the modern railway demands a complex electrical system, which for the P2 will be based closely on Tornado’s. This will include LED lighting and headlamps of the same design as carried by the A1. The one major addition will be of the European Rail Traffic Management System (ERTMS), which will be fitted to Tornado by the time 2007 steams. The electrification and re-signalling of the Great Western Main Line will see ERTMS introduced on it from 2016, and it is currently scheduled to be introduced on the East Coast Main Line in 2019, so its fitting will be essential for the new P2 to traverse its predecessors’ home turf.

Technical details
2007 will have the same design of boiler as Tornado. This is 17 inches shorter than that on the original P2s, but boiler design was already moving away from longer barrels by the mid-30s, as it provided little benefit. Accordingly, the smokebox will be 17 inches longer, which does have benefits, as it damps individual exhaust events and makes them less likely to drag the fire forward.

The new P2 will have smaller cylinders (19.75in diameter) than previous members of the class (21in). This is in large part for gauging purposes: Tornado can run the full length of the ECML without having to slow for platforms, which some older locomotives cannot do (platform edges having been extended over the last 30 years), and the same will be true of Prince of Wales. The cylinders will “almost certainly” be steel, not cast iron.

The boiler will have detailed modifications relative to the design as originally devised for Tornado, which will also be put on the A1 at its overhaul at the end of 2014. It will operate at 250psi rather than 220 on 2001 Cock o’the North; the higher boiler pressure and smaller cylinders will keep the tractive effort of the original P2s, indeed 2007’s will be slightly higher. The possibility of having three boilers in total between the two locomotives, to allow for more rapid overhauls, will be considered.

The type of valve gear to be fitted to 2007 is still to be decided. It’s known that British Caprotti gear will fit, and the initial thinking was that would be preferable to the Lentz rotary cam poppet gear that Gresley ultimately took against. However, research has shown that the Lentz gear was developed into the 1940s, in the USA (and, “being Americans, they developed it properly”). Extensive technical literature exists around the developed forms of the gear, so more research is being undertaken and Lentz is still an option under consideration. (As an aside, only c.70% of drawings for the P2 have been located, compared to c.90% for the A1 design – a portion of this difference is accounted for by the Lentz valve gear being an “off the shelf” product and full details probably never being supplied to Doncaster; the archive of the Associated Locomotive Equipment Company, which supplied it, has been tracked down and is being explored.) Walschaerts valve gear has not been totally ruled out – it is after all a known quantity – though it would spoil the aesthetics in terms of similarity to 2001.

Prince of Wales will have an axle load 20 tons, 2.5 lighter than Tornado; it may creep up to 21 when the air brake gear is fitted.

In respect of wheels, LNER practice was to cast the balance weight in the wheel, rather than adding the weights on, then pouring the lead in once the correct weight had been found. The latter (LMS) method requires two patterns and the former five, so the non-LNER method will be used.

It is clear that there will be a small number of preserved lines that the P2 can’t visit but Tornado can; that said, it will conform to the same gauging as Tornado, so will be able to get to locations traditionally inaccessible to relatively wide steam locomotives such as Dover.

Smokebox dart
2007’s smokebox dart, as manufactured by James May, was on display at the event

Several minor points of interest emerged during the presentations and the question and answer session, and are presented here in no particular order.

The original P2s atracted significant media interest when they were new, to the extent that 2001 starred in a “feature film” entitled ‘Cock o’the North’ for which a mocked-up cab section was made. Sadly no surviving footage from the film is known to exist.

It is intended for 2007 to carry the name ‘Duke of Rothsay’ when operating in Scotland, as this is the formal title of the Prince of Wales north of the border. This plan needs to be formally agreed with the Palace, but it is fully expect that will not present an obstacle. A meeting with Palace officials to discuss this and other issues is imminent.

A question from the floor asked about the relationship between the P2 Steam Locomotive Company and the Doncaster P2 group. Mark Allatt observed that the latter has been going for 17 or 18 years, in which time it has raised about £35K. The two groups have met: the Doncaster group asked for access to the VAMPIRE work, and the P2SLC asked for details of Doncaster’s finance people, to discuss sharing the cost; no subsequent meeting has been arranged.

The P2SLC is looking at apprenticeship/s and a training scheme during the construction of Prince of Wales; whereas with Tornado the works were often open for 2-3 days a week, for the P2 it will be 5-6 days a week, so such a scheme is now much more feasible.

A question was asked regarding 90mph running of the P2 and the reported negotiations with Network Rail to secure it for Tornado. While the speakers would not be drawn on the latter point, it was noted that unlike the A1s, the P2s don’t have a pedigree of 90mph running: the highest recorded speed of an A1 was (depending on what source one prefers) c.112mph, and they were often recorded at or near 100; the P2’s top speed on 2001’s test runs was into the 80s. However, nothing will be put into the design that would prevent 90mph running; but there appears to be no compelling reason to go above 75 (other than perhaps to keep out of the way of service trains).

Further roadshows
The roadshows will be repeated in the times and places below – heading north along the route operated by the P2s, in fact. Registration is not absolutely required, but would help the organisers forecast numbers for the events – click here to register.

Presentations start at 11am and last for approximately two hours, including time for questions. If there is sufficient demand, a second roadshow will follow at 2pm.

22nd March – York, National Railway Museum, Leeman Road, York, YO26 4XJ

5th April – Darlington, The Dolphin Centre, Horse Market, Darlington, County Durham DL1 5RP

26th April – Edinburgh, The Balmoral, 1 Princes Street, Edinburgh, EH2 2EQ

17th May – Aberdeen, School of Engineering, Garthdee Campus, Robert Gordon University.