Data from A E Durrant, The Smoke That Thunders (Harare, Zimbabwe: African Publishing Group, 1997), pp. 108-118. Works numbers were 7581-7583, in service in November 1953; 7586 in December; 7584-7585, 7587-7588 in January 1954; 7589-7592, 7599 February, 7600-7604 in March.
Based in large part on the Class 14 Beyer-Garratts delivered in 1929-1930 (Locobase 717), these postwar engines reworked the design of the 8" (203 mm) piston valves to increase valve travel by 50% to 5 7/16" (138 mm). The engines' pony trucks had roller bearings when delivered. Durrant wrote that the 14As were "very free-running engines" that were "able to bowl along at 55-60 mph [89-97 km/h] when given the opportunity."
Sanctions imposed on Rhodesia beginning in 1975 in response to the country's attempt to preserve white-minority rule led to an extension of the 14As' service. So the railway refurbished the engines in 1979-1981. All of the coupled axles received spherical roller bearings housed in cannon boxes lined with manganese steel. Durrant observed that these made them "thoroughly modern units of motive power."
As often happened with updates in any railway, the class now presented a variety of tank and bunker designs that Durrant's 1988 survey managed to reduce to:
Old tank and bunker 519
Old tank, new, larger bunker 510
New, larger tank, old bunker 508-509, 513-514, 516-518
New tank, new bunker 511-512, 515, 520-525.
The refurbished locomotives weighed 6-7 tons (13,440 lb-15,680 lb/6,096-7,112 kg) more than the original 14As, which raised their axle loading to 14.5 long tons (32,480 lb/14,733 kg).
All of the class was finally retired from active service in 1993; several remained available for tourist operations.
Data from A E Durrant, The Smoke That Thunders (Harare, Zimbabwe: African Publishing Group, 1997), pp. 101-102; and "Rhodesia Railways-Design 1136", Beyer-Garrrat Patent Articulated Locomotives (Manchester, England: Beyer-Peacock & Company Limited, 1931), archived on flickr's Historical Railway Images at [], et seq, p 50. First batch work numbers 6510-6515 in April 1929, 6616-6625 in March 1930.
Compared to the 13th class of 1926 described in Locobase 716, this class adopted several changes of which Durrant heartily approved. The frame was now made of bars rather than plates and the carrying trucks were proper "pony" trucks with larger bearings. The first 14s kept the "absurdly short" (3 3/4"/95 mm) valve travel, but the steam ports were more direct and, thus, free-flowing. The firebox now had a slight rake, the boiler rode 9" (229 mm) higher, the leading tanks top edges were chamfered for better visibility, and the coal bunker had higher sides to encourage better self-trimming.
The last ten delivered in 1930 had slightly greater in-service weight of 282,240 lb (128,022 kg).
For some reason, 234 went out of service in January 1938.
The first eight locomotives--215-220, 231-232--were sold with the B&M's Beira line in October 1949 to the CFM Estado of Mozambique; they received new road numbers 901-908.
The rest of the class had its lifetimes extended by sanctions (as Rhodesia attempted to retain white-minority rule) and the engines served as shunters (switchers). 236-237 were last used in 1973, 235 was retired in 1974, 233 followed in 1975. 239, 238, and 240 remained available for another seven years before their retirements in 1982, 1983, and 1984, respectively.
Class 14A were a thorough reconsideration of the small Garratt; see Locobase 16017.
Data from Gavin Hamilton's excellent compilation of Garratt data posted at [] (6 September 2005).
See also A E Durrant, The Smoke That Thunders (Harare, Zimbabwe: African Publishing Group, 1997), pp. 119-139; and "Garratt 398 - Ex Rhodesia Railways Garratt locomotive" history and assessment on the New Zealand Steam Incorporated website at [], last accessed 22 July 2020. 399-413 (7351-7365) followed in 1952.
These were 15th class Double Hudson Garratt locomotives (Locobase 721) with a higher boiler pressure and more firebox heating surface, that latter now including thermic syphons in addition to the arch tubes.
Tufnell (1986) noted that they ran 10,000 miles per month in service and continued on much longer than expected. Plans to retire them in 1980 were foregone because of financial limitations imposed transformation of Rhodesia to Zimbabwe through independence as well as the 1970s round of oil price hikes. Instead, this class was refurbished and renamed and operated at least into the mid-1990s.
The Ultimate Steam Page ([], last accessed 16 May 2010), briefly describes the update program: "Working with local contracting firms, the National Railways of Zimbabwe, (NRZ) restored nearly 90 Garratts. Each engine was given a thorough rebuild, and was converted to roller bearings on all axles (if not already equipped) to improve reliability, availability, and power. Many of the Class 15 4-6-4+4-6-4's received locally designed improved exhaust systems."
The local design was a six-jet "pepper pot", each jet measuring 63.5 mm (2 1/2"). Bulwayo fitt the assembly inside a 20th class chimney (North American "stack") that replaced the smaller-diameter original.
Data from Gavin Hamilton's excellent compilation of Garratt data posted at [] (6 September 2005); and A[rthur] E[dward] Durrant, Garratt Locomotives of the World (revised edition) (Newton Abbott, UK: David & Charles, 1981), p.157-158 . See also A E Durrant, The Smoke That Thunders (Harare, Zimbabwe: African Publishing Group, 1997), pp. 119-139. Franco Belge work numbers 2963-2972.
Double Hudson Garratts on sub contract of the 15th class from Beyer Peacock (Beyer work numbers 7555-7564). Firebox heating surface area included arch tubes and thermic syphons. All four cylinders were served by 8" (203 mm) piston valves.
The RR tested the Giesl exhaust ejectors and found them to have lived up to their billing. But broadly supported ecomoic sanctions protesting the racial-separatist policies of Southern Rhodesia, the self-liberating government deckared in 1965 As a result, the RR couldn't purchase any more Giesl ejectors. But the local shops devised a "pepper-pot" blastpipe using six jetsand adopted a 20th class chiminey to contain it. "This also gave excellent results," wrote Durrant "...nearly as good as a Giesel ejector properly adjusted., and far better than a mal-adjusted ejector." All 15ht and 15A engines received pepper pots.
See Locobase 722 for details on 1980s rebuilt program.
Data from Martyn Bane's archived copy of the report "4-6-4+4-6-4 3 ft. 6 in Gauge Beyer-Garratt Locomotives for the Rhodesia Railways", reprinted from 9 August 1940 Railway Gazette (Manchester: Beyer, Peacock & Co, Ltd.) with additional pages supplied by Beyer, Peacock. Last accessed 23 September at [] . See also A[rthur] E[dward[ Durrant, The Smoke That Thunders (Harare, Zimbabwe: African Publishing Group, 1997), pp. 119-139.
The first four in this passenger-hauling class appeared in 1940, the later examples being delivered after World War II (275-284 (7228-7237), and 364-383 (7260-7279) (1947)).
Obviously derived from the 16th-class Double Mikado Garratts that first appeared in 1929, these engines had taller drivers on fewer driven axles, but more axles altogether. The Belpaire firebox included four arch tubes in its heating surface. Steam admission to the cylinders came through 9" (229 mm) piston valves with 6" (152 mm) travel.
They were a great success on the 484-mile (779-km) Mafeking-Bulwayo run, earning a reputation for light maintenance demands, free running, and durability. New Zealand's Steam Incorporated, owner of the 15A class 398 (Locobase 722) offered a summary of the reasons the 15 class engines proved so valuable to their railway:
"They could haul 550 ton passenger trains at 50 mph (81 kph), and often faster, on the level and at not less than 20 mph (32 kph) on grades of 1 in 66. And they could deal with 1,000 ton freight trains. The maximum axle load did not exceed 13+ tons [29,680 lb] in working order and their boilers were interchangeable with those fitted to the 16th class 2-8-2+2-8-2's [Locobase 729], thus having a working pressure of 180 psi."
Steam Incorporated added: "Because of their low operating costs, low maintenance requirements and the ability to run fast when required, the 15's were the locomotives most used when there was a choice and so they had a tendency to accumulate some considerable mileages."
74 15-Class locomotives were supplied (including 30 15As [Locobases 722-723]), making this the second most numerous class of Garratts to have been built.
NB: Tube length is between sheets.
Data from Gavin Hamilton's excellent compilation of Garratt data posted at []
(6 September 2005). See also data from A E Durrant, The Smoke That Thunders (Harare, Zimbabwe: African Publishing Group, 1997), pp. 159-160. Works numbers were 7498-7527 in 1953
Big postwar batch similar to earlier 16th class Double Mikado Garratts (Locobase 719), but operating at a higher boiler pressure and sporting 12% more direct heating surface. In terms of design, the 16A showed the impact of several upgrades. These included "streamlined" bunker and tank ends, long lap and long travel valves, roller bearings on the pony truck axles.
But the class suffered from very indifferent production standards that Durrant attributed to the supplanting of "former proud traditions of management by engineers, and work performed by craftsmen ...[by] management by accountants of radical trade union 'workers'." From May 1957 to October 1958, half of the class required repairs. These same engines were refurbished in 1979-1980 with all axles turning in roller bearings and much larger fuel and water capacities
Once problems were resolved, the 16As were "finally excellent machines" wrote Durrant. In the final form, most had . Roller bearings allowed the four-foot drivers to turn at better than 350 rpm as they pulled passenger trains at "well over" 50 mph (81 kph).
While neither the three loaned to Mozambique nor those turned over to Zambia upon that company's liberation fared well, several of the RR engines--601,603, 605-606,609-610, 614-615 operated into the 1990s.
Data from A E Durrant, The Smoke That Thunders (Harare, Zimbabwe: African Publishing Group, 1997), pp. 142-145. See also Gavin Hamilton's excellent compilation of Garratt data posted at []
(6 September 2005): "Rhodesia Railway-Design 1146", Beyer-Garrrat Patent Articulated Locomotives (Manchester, England: Beyer-Peacock & Company Limited, 1931), archived on flickr's Historical Railway Images at [], et seq, p. 56. First batch had BP works numbers of 6562-6569. Beyer later delivered 259-264( 6877-6882) of the same class in 1937 and 265-270 (6899-6904) in 1938.
As big as the 13th (Locobases 716) and 14th class (Locobases 717) a Double Prairie Beyer-Garratts (Locobase 717) might have seemed on the steep Cape Gauge line, these Double Mikado Garratts ushered in a substantial increase in power. Like virtually all Beyer-Garratts, these presented the four-cylinder, simple expansion layout,with piston valves and Schmidt superheaters, but steamed in a round-topped firebox.. They also featured the relatively light axle loadings required by the 60 lb/yard (30 kg/metre) rail. Firebox heating surface area included 23 sq ft (2.14 sq m) of arch tubes.
Each cylinder's diameter measured 2 1/2" (63.5 mm) greater than the earlier engines and considerably more adhesion weight on two more axles. "Dusty" Durrant wrote that the design carried over many elements from the earlier engines, including the "ultra-short" steam lap and valve travel.
Their operating area included traversing the Victoria Falls bridge, scaling 2% grades, and negotiating 7-chain (462 ft) curves. In 1931, B-P reported these "most excellent" machines had been "immediately successful" hauling 700 short tons (625 long tons) and "not given the slightest anxiety under service conditions."
Durrrant reported that 16th classe locomotives often operated in tandem, "making a formidable Garratt combination totalling 100,000 lb of tractive effort and more than 100 square feet of grate area." He added that these figures were "more in line with practice in the USA!"
Water and fuel soon proved inadequately provided in the original setup. Coal capacity later increased to 8 3/4 long tons (9.8 short tons) and water to 6,180 Imperial gallons (28,070 litres
( Postwar 16A profiled in Locobase 720.)
After long careers on the RR, the 16th class engines were among the first to be retired in favor of diesels. "[B]ut", Durrant added, "being sturdy and powerful machines they were in demand elsewhere, nine being sold in 1964 to the Bengula Railway in Angola, where their principal dimensions almost exactly matched the standard CFB Garratts of 4-8-2+2-8-4 wheel arrangement." All were classed as 10a class E and converted to eucalyptus burning. The CFB added a cage to the tender to hold the logs, which were grown in specially planted groves.
601-602, 607, 610-611, 615-617, and 619 respectively took numbers 388, 381, 389, 382, 385, 383, 386, 384, 387.
These also often worked as a team in a "dupla", which used one locomotive at the head of the train and another cut into the middle of the train. (Locobase thinks of the 21st century "distributed power" using two or more diesels, but the Garratts were fully crewed and run independently.)
Several other 16th class engines went to collieries. Douglas Colliery ultimately owned three (603,-604, 612). 606, 618 went to the Enyati Colliery, Landau 3 Collier bought 605, Transvaal Navigation Colliery ran the 609.
Data from Gavin Hamilton's excellent compilation of Garratt data posted at [] (6 September 2005). See also data from A E Durrant, The Smoke That Thunders (Harare, Zimbabwe: African Publishing Group, 1997), pp. 159-160. Works numbers were 7066-7074 in 1944.
Part of a War Department build for the Congo, Gold Coast (Ghana), and Rhodesia (Zimbabwe). Durrant wrote that, given the tendency to build basic "austerity" designs to meet wartime demands, it was "a tribute to the Garratt concept that it was considered suitable in such days for wartime construction and use."
The class served its purpose in Rhodesia, but when the Beira line was sold to the Portuguese in October 1949, the entire class went with it as CFM Estado's 981-989.
Data from Gavin Hamilton's excellent compilation of Garratt data posted at [] (6 September 2005); and A[rthur] E[dward] Durrant, Garratt Locomotives of the World (revised edition) (Newton Abbott, UK: David & Charles, 1981), p.151-153. See also A E Durrant, The Smoke That Thunders (Harare, Zimbabwe: African Publishing Group, 1997), pp. 170-172.
Double Mountain Garratts with BP #s 7685-7699. Also included 20A-class 715-720 (7780-7785) in 1957 that had slightly more total weight (511,833 lb/232,164 kg).
OS Nock (RWC VI, pl 73) notes that these Garratts were the most powerful engines on the Rhodesia Railways. They were "free-running" and "exceptionally smooth in riding" despite their small coupled wheels and operated 1,500-1,700-ton freights at speeds up to 45 mph. Their bailiwick was the main line north out of the Port of Bulawayo to the Victoria Falls.
Durrant wrote that these engines incorporated a number of modern systems. They were the only Rhodesian engines to be mechanically stoked, used Beyer Peacock self-adjusting pivots. Although delivered with plain bearing on all adhesion axles, the engines received roller bearings on every axle in 1979-1982.
Durrant's Garratts account ascribes many of the main frame fractures to the decision not to base the design on a cast-steel frame. His Smoke that Thunders entry calls out declining Beyer Peacock quality for the series of parts failuers and repair delays: In his opinion, "Thewe were early victims of the current [late 20th century] malaise of management by accountants, combiined with radical trade unionism, which has been the cause of mu ch of the world's poor economic performance since the age of steam railway dominance."
Durrant goes on to compare the relative competences of the railway establishments of Zambia (formerly Northern Rhodesia) and the shops centered at Bulawayo. Zambia inherited many of the 20th class engines, but much of the infrastructure remained in Southern Rhodesia. The former could not afford to invest in the maintenance of steam locomotives, while the latter benefited from decades-long self-reliance. So it was in the latter that most of the 20th class Garratts continued to operate until 1993.
Principal Dimensions by Steve Llanso of Middle Run Media | |||||
---|---|---|---|---|---|
Class | 14A | 14th | 15A | 15A - FB | 15th |
Locobase ID | 16017 | 717 | 722 | 723 | 721 |
Railroad | Rhodesia Railways | Rhodesia Railways | Rhodesia Railways | Rhodesia Railways | Rhodesia Railways |
Country | Rhodesia | Rhodesia | Rhodesia | Rhodesia | Rhodesia |
Whyte | 2-6-2+2-6-2 | 2-6-2+2-6-2 | 4-6-4+4-6-4 | 4-6-4+4-6-4 | 4-6-4+4-6-4 |
Number in Class | 18 | 16 | 30 | 10 | 34 |
Road Numbers | 508-525 | 215-220, 231-240/901-908 | 384-413 | 414-423 | 271-284, 364-383 |
Gauge | 3'6" | 3'6" | 3'6" | 3'6" | 3'6" |
Number Built | 18 | 16 | 30 | 10 | 34 |
Builder | Beyer, Peacock | Beyer, Peacock | Beyer, Peacock | SA Franco-Belge, Raismes | Beyer, Peacock |
Year | 1953 | 1929 | 1949 | 1952 | 1940 |
Valve Gear | Walschaert | Walschaert | Walschaert | Walschaert | Walschaert |
Locomotive Length and Weight | |||||
Driver Wheelbase (ft / m) | 8.75 / 2.67 | 17.50 / 5.33 | 10.50 / 3.20 | ||
Engine Wheelbase (ft / m) | 19.25 / 5.87 | 40.50 / 12.34 | 31.44 / 9.58 | ||
Ratio of driving wheelbase to overall engine wheelbase | 0.45 | 0.43 | 0.33 | ||
Overall Wheelbase (engine & tender) (ft / m) | 63 / 19.20 | 63 / 19.20 | 84.25 / 25.68 | ||
Axle Loading (Maximum Weight per Axle) (lbs / kg) | 30,296 / 13,742 | 30,240 / 13,717 | 35,616 / 16,155 | 35,616 / 16,155 | 29,680 / 13,463 |
Weight on Drivers (lbs / kg) | 181,720 / 82,427 | 181,440 / 82,300 | 201,600 / 91,444 | 201,600 / 91,444 | 181,440 / 82,300 |
Engine Weight (lbs / kg) | 294,941 / 133,783 | 282,240 / 128,022 | 418,298 / 189,737 | 418,298 / 189,737 | 402,080 / 182,381 |
Tender Loaded Weight (lbs / kg) | |||||
Total Engine and Tender Weight (lbs / kg) | |||||
Tender Water Capacity (gals / ML) | 4320 / 16.36 | 5220 / 19.77 | 8400 / 31.82 | 8400 / 31.82 | 8400 / 31.82 |
Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT) | 7.70 / 7 | 7.70 / 7 | 13.80 / 13 | 11 / 10 | 11 / 10 |
Minimum weight of rail (calculated) (lb/yd / kg/m) | 50 / 25 | 50 / 25 | 56 / 28 | 56 / 28 | 50 / 25 |
Geometry Relating to Tractive Effort | |||||
Driver Diameter (in / mm) | 48 / 1219 | 48 / 1219 | 57 / 1448 | 57 / 1448 | 57 / 1448 |
Boiler Pressure (psi / kPa) | 180 / 1240 | 180 / 1240 | 200 / 1380 | 200 / 1240 | 180 / 1240 |
High Pressure Cylinders (dia x stroke) (in / mm) | 16" x 24" / 406x610 (4) | 16" x 24" / 406x610 (4) | 17.5" x 26" / 445x660 (4) | 17.5" x 26" / 445x660 (4) | 17.5" x 26" / 445x660 (4) |
Tractive Effort (lbs / kg) | 39,168 / 17766.33 | 39,168 / 17766.33 | 47,496 / 21543.85 | 47,496 / 21543.85 | 42,746 / 19389.28 |
Factor of Adhesion (Weight on Drivers/Tractive Effort) | 4.64 | 4.63 | 4.24 | 4.24 | 4.24 |
Heating Ability | |||||
Tubes (number - dia) (in / mm) | 184 - 2" / 51 | 184 - 2" / 51 | 214 - 2" / 51 | 214 - 2" / 51 | 214 - 2" / 51 |
Flues (number - dia) (in / mm) | 32 - 5.25" / 133 | 32 - 5.25" / 133 | 39 - 5.25" / 133 | 39 - 5.25" / 133 | 38 - 5.25" / 133 |
Flue/Tube length (ft / m) | 12 / 3.66 | 12 / 3.66 | 13.03 / 3.96 | 13.03 / 3.97 | 12.99 / 3.96 |
Firebox Area (sq ft / m2) | 174 / 16.16 | 174 / 16.16 | 212 / 19.70 | 254 / 23.60 | 212 / 19.70 |
Grate Area (sq ft / m2) | 38.60 / 3.59 | 38.80 / 3.60 | 49.60 / 4.61 | 49.60 / 4.61 | 49.50 / 4.60 |
Evaporative Heating Surface (sq ft / m2) | 1841 / 171.03 | 1850 / 171.87 | 2336 / 217.02 | 2385 / 221.57 | 2336 / 217.02 |
Superheating Surface (sq ft / m2) | 374 / 34.75 | 380 / 35.30 | 494 / 45.89 | 494 / 45.89 | 494 / 45.89 |
Combined Heating Surface (sq ft / m2) | 2215 / 205.78 | 2230 / 207.17 | 2830 / 262.91 | 2879 / 267.46 | 2830 / 262.91 |
Evaporative Heating Surface/Cylinder Volume | 164.81 | 165.62 | 161.37 | 164.75 | 161.37 |
Computations Relating to Power Output (More Information) | |||||
Robert LeMassena's Power Computation | 6948 | 6984 | 9920 | 9920 | 8910 |
Same as above plus superheater percentage | 8129 | 8171 | 11,606 | 11,606 | 10,425 |
Same as above but substitute firebox area for grate area | 36,644 | 36,644 | 49,608 | 59,436 | 44,647 |
Power L1 | 7834 | 7915 | 10,293 | 10,633 | 9263 |
Power MT | 570.25 | 577.04 | 675.36 | 697.67 | 675.31 |
Principal Dimensions by Steve Llanso of Middle Run Media | ||||
---|---|---|---|---|
Class | 16A | 16th | 18th class | 20th / 20A |
Locobase ID | 720 | 719 | 4587 | 724 |
Railroad | Rhodesia Railways | Rhodesia Railways | Rhodesia Railways | Rhodesia Railways |
Country | Rhodesia | Rhodesia | Rhodesia | Rhodesia |
Whyte | 2-8-2+2-8-2 | 2-8-2+2-8-2 | 2-8-2+2-8-2 | 4-8-2+2-8-4 |
Number in Class | 30 | 20 | 9 | 21 |
Road Numbers | 620-649/601-615 | 221-228, 259-270/- | 4409-4417/281-289/981-989 | 700-720 |
Gauge | 3'6" | 3'6" | 3'6" | 3'6" |
Number Built | 30 | 20 | 9 | 21 |
Builder | Beyer, Peacock | Beyer, Peacock | Beyer, Peacock | Beyer, Peacock |
Year | 1953 | 1929 | 1943 | 1954 |
Valve Gear | Walschaert | Walschaert | Walschaert | Walschaert |
Locomotive Length and Weight | ||||
Driver Wheelbase (ft / m) | 17.50 / 5.33 | |||
Engine Wheelbase (ft / m) | 49.50 / 15.09 | |||
Ratio of driving wheelbase to overall engine wheelbase | 0.35 | |||
Overall Wheelbase (engine & tender) (ft / m) | 73.62 / 22.44 | |||
Axle Loading (Maximum Weight per Axle) (lbs / kg) | 32,794 / 14,875 | 29,904 / 13,564 | 29,411 / 13,341 | 38,080 / 17,273 |
Weight on Drivers (lbs / kg) | 262,349 / 119,000 | 237,440 / 107,701 | 232,288 / 105,364 | 305,312 / 138,487 |
Engine Weight (lbs / kg) | 378,963 / 171,895 | 337,456 / 153,068 | 340,032 / 154,236 | 500,416 / 226,985 |
Tender Loaded Weight (lbs / kg) | ||||
Total Engine and Tender Weight (lbs / kg) | ||||
Tender Water Capacity (gals / ML) | 6000 / 22.73 | 5400 / 20.45 | 5520 / 20.91 | 9600 / 36.36 |
Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT) | 9.40 / 8.50 | 6.60 / 6 | 9.90 / 9 | 15.40 / 14 |
Minimum weight of rail (calculated) (lb/yd / kg/m) | 55 / 27.50 | 49 / 24.50 | 48 / 24 | 64 / 32 |
Geometry Relating to Tractive Effort | ||||
Driver Diameter (in / mm) | 48 / 1219 | 48 / 1219 | 45.50 / 1156 | 51 / 1295 |
Boiler Pressure (psi / kPa) | 200 / 1380 | 180 / 1240 | 180 / 1240 | 200 / 1380 |
High Pressure Cylinders (dia x stroke) (in / mm) | 18.5" x 24" / 470x610 (4) | 18.5" x 24" / 470x610 (4) | 19" x 24" / 483x610 (4) | 20" x 26" / 508x660 (4) |
Tractive Effort (lbs / kg) | 58,183 / 26391.40 | 52,364 / 23751.94 | 58,268 / 26429.95 | 69,333 / 31448.96 |
Factor of Adhesion (Weight on Drivers/Tractive Effort) | 4.51 | 4.53 | 3.99 | 4.40 |
Heating Ability | ||||
Tubes (number - dia) (in / mm) | 214 - 2" / 51 | 214 - 2" / 51 | 282 - 2" / 0 | |
Flues (number - dia) (in / mm) | 39 - 5.25" / 133 | 39 - 5.25" / 133 | 36 - 5.5" / 0 | |
Flue/Tube length (ft / m) | 13.03 / 3.97 | 13 / 3.96 | 11.75 | 13.54 / 4.13 |
Firebox Area (sq ft / m2) | 212 / 19.70 | 212 / 19.70 | 212 / 19.70 | 233 / 21.65 |
Grate Area (sq ft / m2) | 49.60 / 4.61 | 49.60 / 4.61 | 51.30 / 4.77 | 63.10 / 5.86 |
Evaporative Heating Surface (sq ft / m2) | 2343 / 217.67 | 2338 / 217.21 | 2540 / 236.06 | 3024 / 280.94 |
Superheating Surface (sq ft / m2) | 494 / 45.89 | 480 / 44.59 | 470 / 43.68 | 748 / 69.49 |
Combined Heating Surface (sq ft / m2) | 2837 / 263.56 | 2818 / 261.80 | 3010 / 279.74 | 3772 / 350.43 |
Evaporative Heating Surface/Cylinder Volume | 156.90 | 156.56 | 161.25 | 159.93 |
Computations Relating to Power Output (More Information) | ||||
Robert LeMassena's Power Computation | 9920 | 8928 | 9234 | 12,620 |
Same as above plus superheater percentage | 11,606 | 10,446 | 10,711 | 15,144 |
Same as above but substitute firebox area for grate area | 49,608 | 44,647 | 44,266 | 55,920 |
Power L1 | 8410 | 7442 | 6785 | 9819 |
Power MT | 565.38 | 552.79 | 515.17 | 567.21 |