Midland 0-6-4 Locomotives in Great_Britain

Class Details by Steve Llanso of Sweat House Media

Class D3P (LMS) (Locobase 2319)

See Ahrons (1927) for data. See also "Six-Coupled Bogie Tank Locomotive, Midland Ry.," The Locomotive Magazine, Vol XIII (15 June 1907), p. 98; . Charles Lake,Locomotives of 1907 (London: Percival Marshall & Co, 1907), presented on [], last accessed 31 January 2009,

RM Deeley's inside-cylinder tank engine class, which nicknamed the Flatirons. Charles Lake noted that the unusual arrangement had some advantages: "The presence of the four-wheeled bogie at the trailing end permits of a greater coal and water carrying capacity than when a single pair of radial wheels is employed." The leading driven axle was mounted in a Cartazzi axle with lateral play and the trailing bogie also had side play. Also, the small ends of the connecting rods (the ends in the crossheads) had a ball-and-socket junction and the side rods connecting the driving axle to the others had bushings as well.

Lake's comments on their design and service use shows the North American reader a different way of handling local traffic: "These new locomotives represent a considerable advance in the practice of the Midland Railway, where hitherto large tank engines have not been the rule. With their increased cylinder and boiler capacities, ample adhesion weight and general flexibility of wheelbase, they are proving a highly efficient type for working heavy suburban traffic, and they are equally well adapted for goods train service. "

Class Deeley tanks with superheaters (Locobase 20227)

Data from "0-6-4 Superheater Tank Engines,, Midland Ry.," The Locomotive Magazine, Volume XXVIII [28] (15 April 1922), p. 95-96.

Locobase 2319 describes RM Deeley's inside-cylinder tank engine as it entered service in 1907. After World War One, Henry Fowler superheated the originals and fitted the boilers with Belpaire fireboxes. Because he found the slide valves worked well enough even with superheated steam given the Midland's method of mechanical lubrication, he did not replace them with piston valves.

He did, however, fit them with his own design of cast-iron superheater header. LM reported that the headers were not rigidly fixed to the header, being mounted instead in jointing rings, which meant they could adjust themselves "to any small inaccuracies in the header."

Principal Dimensions by Steve Llanso of Sweat House Media

ClassD3P (LMS)Deeley tanks with superheaters
Locobase ID2319 20227
CountryGreat BritainGreat Britain
Number in Class404
Road Numbers20002035
Number Built40
Valve GearStephensonStephenson
Locomotive Length and Weight
Driver Wheelbase (ft / m)16.50 / 5.0316.50 / 5.03
Engine Wheelbase (ft / m)28 / 8.5329 / 8.84
Ratio of driving wheelbase to overall engine wheelbase 0.59 0.57
Overall Wheelbase (engine & tender) (ft / m)29 / 8.84
Axle Loading (Maximum Weight per Axle) (lbs / kg)42,336 / 19,203
Weight on Drivers (lbs / kg)117,981 / 53,515124,432 / 56,441
Engine Weight (lbs / kg)162,221 / 73,582171,472 / 77,778
Tender Loaded Weight (lbs / kg)
Total Engine and Tender Weight (lbs / kg)162,221 / 73,582171,472 / 77,778
Tender Water Capacity (gals / ML)2700 / 10.232700 / 10.23
Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT) 3.90 / 4 3.90 / 4
Minimum weight of rail (calculated) (lb/yd / kg/m)66 / 3369 / 34.50
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)67 / 170267 / 1702
Boiler Pressure (psi / kPa)175 / 12.10175 / 12.10
High Pressure Cylinders (dia x stroke) (in / mm)18.5" x 26" / 470x66018.5" x 26" / 470x660
Tractive Effort (lbs / kg)19,756 / 8961.1819,756 / 8961.18
Factor of Adhesion (Weight on Drivers/Tractive Effort) 5.97 6.30
Heating Ability
Tubes (number - dia) (in / mm)242 - 1.75" / 44
Flues (number - dia) (in / mm)
Flue/Tube length (ft / m)10.50 / 3.2010.50 / 3.20
Firebox Area (sq ft / m2)125 / 11.62123.50 / 11.47
Grate Area (sq ft / m2)21.10 / 1.9621.10 / 1.96
Evaporative Heating Surface (sq ft / m2)1331 / 123.701167 / 108.42
Superheating Surface (sq ft / m2)253 / 23.50
Combined Heating Surface (sq ft / m2)1331 / 123.701420 / 131.92
Evaporative Heating Surface/Cylinder Volume164.55144.27
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation36933693
Same as above plus superheater percentage36934357
Same as above but substitute firebox area for grate area21,87525,503
Power L147259812
Power MT264.88521.53

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