5AT Advanced Technology Steam Locomotive

5AT

The 5AT locomotive illustrated in its final form.
Type and origin
Power type Steam
Designer David Wardale
Specifications
Configuration 4-6-0
Gauge 4 ft 8 1⁄2 in (1,435 mm)
Leading dia. 3 ft 0 in (0.914 m)
Driver dia. 6 ft 2 in (1.880 m)
Axle load 20 tonne
Adhesive weight 60 tonne
Loco weight 80 long tons 0 cwt (179,200 lb or 81.3 t)
Total weight 160 long tons 0 cwt (358,400 lb or 162.6 t)
Fuel type Light Oil or Coal
Fuel capacity 7 long tons 0 cwt (15,700 lb or 7.1 t)
Water cap 10,000 imperial gallons (45,000 l; 12,000 US gal)
Boiler pressure 305 psi (2.10 MPa)
Cylinders Two
Cylinder size 17.72 in × 31.5 in (450 mm × 800 mm)
Loco brake Air
Train brakes Air
Performance figures
Maximum speed 113 mph (Max Design Speed 125 mph)
Tractive effort 32,688 lbf (145.40 kN)
Factor of adh. 4 approx

The 5AT Advanced Technology steam locomotive is a conceptual design conceived by the British engineer David Wardale,[1] and first described in his definitive work on modern steam, The Red Devil and Other Tales from the Age of Steam.[2]

Wardale's purpose in putting forward the "Super Class 5 4-6-0" design concept (as he then called it) was to offer a future for steam hauled trains on the main lines in the UK on which the use of heritage traction is likely to be gradually phased out as the speed and density of commercial rail traffic increase.[3]

Work on the project was suspended in March 2012 following completion of a project Feasibility Study and subsequent failure to raise the finance needed to complete the detail design and construction of the locomotive.[4]

Proposal

Wardale's proposal was for a locomotive that would:

The April 1998 edition of the Steam Railway magazine contained an article by Wardale titled "Whither Steam Now?"[5] which included reference to a "locomotive of Class 5 4-6-0 format - calling it a 5GT - that would outperform any British Pacific."

Still described as the 5GT in a Feb 2001 Railway Magazine article titled "Wardale reveals £1.7 million 'new steam' proposal for the heritage market",[6] the name 5AT first emerged in a letter from Alan Fozard to the editor of Steam Railway Magazine issue 259 in June–July 2001,[7] which coincided with the formation of the 5AT Project.[8]

The 5AT in its final conceptual form remained almost identical in size and weight to the BR 5MT, sharing the axle spacings and being just 4 tonnes heavier, with axle loads of 20 tonnes on each driving axle and 10 tonnes on each bogie axle. Where it differed in size from the 5MT was in its tender which was massively enlarged to carry large quantities of fuel and water to extend its operating range. Such a large tender would also have provided space for the locomotive-carried parts of advanced signalling systems such as ERTMS. The 5AT's four-axle tender would have had a gross weight of 80 tonnes with a fuel (light-oil) capacity of 7 tonnes and water capacity of 46 tonnes (12,000 US gallons).

Outline drawing

5AT Locomotive Outline
5AT Locomotive Outline

The 5AT Project

The 5AT Project was established in 2001 with the aim of commercializing Wardale's 5AT locomotive concept and bringing it to reality. The project was spearheaded by a small team of professional engineers, scientists and businessmen and women whose common purpose was to see steam traction continue in main-line operation into the foreseeable future.

Design calculations

The first task undertaken by the project team was to commission David Wardale to undertake the Fundamental Design Calculations for the locomotive. The purpose of these calculations was to verify through detailed calculations that the conceptual design was viable in engineering terms and that it would meet the performance predictions that Wardale had made for it (see below). At the same time, a project website[8] was established.

Wardale completed the Fundamental Design Calculations for the locomotive in late 2004 after 2½ years of almost continuous labour. The work comprises 6100 lines of calculation divided into 26 sections as follows:

Business plan

Since the completion of the Fundamental Design Calculations, the 5AT Project team focussed on the development of a business plan to attract investment in the project. This proved to be a difficult task because of the high development costs that were anticipated for designing and gaining railway approvals for a prototype locomotive, and the limited returns that might be expected from the locomotive's use on tourist and "cruise" trains. It was concluded that the cost of building the locomotive could only be justified if its initial development costs were "written off".

Research

The project team also undertook extensive research into the possibilities of developing alternative designs based around the high efficiency and low maintenance concepts of the 5AT. Particular focus was placed on the possibilities for (coal-fired) steam traction for coal transportation in developing countries such as Indonesia, for which the operating costs were estimated to have been substantially lower than for diesel and electric traction.

5AT Locomotive Performance

Predictions

The performance predicted for the 5AT locomotive are summarized as follows:[14]

Technical advances

The above performance predictions were predicated on several technical advances, mostly developed by Ing. L.D. Porta, all of which have been proven in practice, in most cases on Wardale's SAR Class 26 "The Red Devil" and described in Wardale's book[15] on the subject. These advances are summarized as follows:

Design features

In addition, the locomotive would have incorporated the following features that would have minimized its maintenance requirements and increased its reliability:

Project Suspension

In March 2012, after ten years of development, the decision was made to suspend the project due to lack of financial support.[16] In the project Feasibility Study, it was estimated that the funding required to complete the detail design, manufacture, assembly, testing and main-line approvals for a prototype locomotive was slightly over £10 million ($16M) at 2010 prices. However subsequent "production" locomotives were estimated to cost in the order of £2.5M ($4M), a cost that could have been justified by the anticipated returns from the haulage of luxury high-speed cruise and tour trains for which the concept was targeted. Following suspension of the project the design group re-formed as the Advanced Steam Traction Trust to provide engineering resources for alternative projects either in the form of new designs or in improvements to existing designs.[17]

See also

References

  1. ↑ Chapelon, Andre (2000), La Locomotive a Vapeur (Translation by George. W. Carpenter C.Eng., M.I.Mech.E., Camden Miniature Steam Services, pp. 615–616, ISBN 0-9536523-0-0
  2. ↑ Wardale, David (1998), The Red Devil and Other Tales from the Age of Steam, Published by the author, ISBN 0-9529998-0-3
  3. ↑ Wardale, David (June 2002), Steaming into the Future, Steam Railway Magazine, p. 36
  4. ↑ Wardale, David (March 2012), End of the Line - Time is Called on the 5AT Project, Steam Railway Magazine, pp. 90–94
  5. ↑ Wardale, David, Whither Steam Now?, Steam Railway Issue 216
  6. ↑ Wardale reveals £1.7 million 'new steam' proposal for the heritage market, Railway Magazine Feb 2001 Issue, p. 71
  7. ↑ letter to editor from Dr. Alan Fozard, Steam Railway issue 259 June–July 2001, p. 43
  8. 1 2 5AT.co.uk. 5AT Group http://www.5at.co.uk. Missing or empty |title= (help)
  9. ↑ Wardale, D. (14 August 2002). "General Calculations - Determination of the Target Power & Tractive Effort-Speed Characteristics" (PDF). Wardale Engineering & Associates. Archived from the original (PDF) on 9 December 2008.
  10. ↑ Wardale, D. (14 August 2002). "General Calculations - Determination of the Target Load-Speed-Gradient Curves" (PDF). Wardale Engineering & Associates. Archived from the original (PDF) on 9 December 2008.
  11. ↑ Wardale, D. (15 August 2002). "General Calculations - Preliminary Basic Calculations" (PDF). Wardale Engineering & Associates. Archived from the original (PDF) on 9 December 2008.
  12. ↑ Wardale, D. (3 July 2004). "General Calculations - Tractive Effort Diagrams" (PDF). Wardale Engineering & Associates. Archived from the original (PDF) on 9 December 2008.
  13. ↑ "General Calculations - Preliminary Basic Calculations (final version)" (PDF).
  14. ↑ Wardale, David (2004), GENERAL CALCULATIONS, 1.3.F. PRELIMINARY BASIC CALCULATIONS (final version)., unpublished
  15. ↑ "The Red Devil and Other Tales from the Age of Steam". 5AT.co.uk. Archived from the original on 6 February 2010.
  16. ↑ "The AT5 - Steaming Ahead with Advanced Technology". AT5.co.uk. 5AT Group. Retrieved 9 December 2015.
  17. ↑ "ATS Group". Advanced Steam Traction Trust. AST Group. Retrieved 9 December 2015.

External links

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