Most data from "Four-Cylinder Compound Locomotives, North Eastern Ry.," The Locomotive Magazine, Vol XII (15 May 1906), p. 73. See also O S Nock, Locomotives of the North Eastern (1954)
This was a Smith compound, but of the 4-cylinder rather than the more characteristic 3-cylinder variety. They were an unusual sight on the North Eastern because of the square-topped Belpaire firebox they used.
Nock comments that dynamometer car tests showed these compounds to be "markedly superior to the Class V engines." 730 had Stephenson link, 731 Walschaerts radial valve gear driving HP valves of 7 1/2" diameter and LP valves measuring 10" across. (731 would be the only NER engine ever to use Walschaerts gear.)
"These two engines," Nock asserts, "were in very truth masterpieces of locomotive design: extremely powerful ...and graceful to a high degree from whatever angle they were viewed."
Data from Richard Marsden, "The Worsdell C8 (NER Class 4CC) 4-4-2 Atlantics" in his online LNER Encyclopedia at [], last accessed 23 October 2014.
There were only two of these four-cylinder compounds designed by Walter Mackersie Smith, an assistant to Wilson Worsdell. The pair had four cylinders driving the lead coupled axle. Each set of outside HP and inside LP cylinders drove cranks that were offset 180 degrees Two piston valves located inside the frames drove two LP cylinders through inside admission ports and the two outside cylinders through rocking levers. 730 used an inside link motion while 731's valves were actuated by Walschaert gear.
Marsden observes that Smith's design was "immediate success and in December 1907, Worsdell authorised the building of ten more with Walschaerts valve gear, and the C8 may have become a standard NER type."
Smith's plans for a class of compounds were defeated by his death in October 1906, five months after the pair were introduced and a demand by his executors for royalty payments. The NER Board chose to cancel the ten-engine order instead.
Despite the conflict, the NER valued the surviving duo, rating them well above most other express designs. Superheating the two surviving 4CCs occurred in 1915. The engines had relatively capacious boilers and the flues and elements seemed to have fit easily, as the review of the heating surface areas would suggest.
Taken into the LNER as class C8.
Data from Ahrons (1927) and Railway World (12 May 1911), p. 372. See also [] (visited November 2002) -- then the London & North Eastern Railway Locomotives page; Richard Marsden's LNER Encyclopedia [], last accessed 11 January 2016, whose superheater area Locobase adopts in the specifications; and "Recent NER Locomotives Class 'Z1' Superheater Engines, Atlantic Type, Three Cylinders", Locomotive Magazines, Volume XIX [19] (15 January 1913), pp. 13-14. For the "semi-uniflow" 2212, see "Three-Cylinder 'Uniflow' Locomotive, North Eastern Railway", Locomotive Magazine, Volume XXV [25], No 323 (15 July 1919), pp. 101-103. For the trailing-truck booster, see "Articulated Locomotives:Their Evolution and Advantages", Railway Wonders of the Worlds at [], last accessed 5 December 2020.
Designed by Vincent Raven and built at the same time as the Zs, but given Schmidt superheaters and cylinder diameters greater by 1" (25.4 mm). The comparison clearly favored the Z1s and a later batch of 30 built at the North Eastern's Darlington shops also were superheated. LM's 1913 report said that these were the first express engines in England to combine manufacture of all three cylinders and their 7 1/2" (191 mm) piston valves in one casting. (Ahrons gives a slightly lower evaporative heating surface of 1,476 sq ft [137.13 sq m]; this may reflect the difference between the two batches.)
The class was put to work hauling 350-400 ton trains between York and Edinburgh. They averaged 53.8 mph (85.5 kph) over the 80.5 miles (130 km) between York and Newcastle and 50-54 mph (80.5-90 kph) over the 124.5 miles (200.5 kph) from Newcastle to Edinburgh.
In tests, these engines developed 1,090 drawbar horsepower pulling a 545-ton load at 58 mph. OS Nock (1954, Locos of the NER) reported that 1924 trials showed the three-cylinder Z1s to be significantly better than their two-cylinder V1 predecessors. They burned 25% less coal per drawbar horsepower hour and consumed 17% less water. By then, an average Z engine had traveled farther between repairs, and stretched the wear of the outer tire on the drivers much further as well..
The London & North Eastern Railway Locomotives page offered an impressive variety of experiments conducted on members of this class. For one thing, the last in the class (2212) was built with Stumpf Uniflow cylinders. (The 1919 LM article describes the use of piston valves as auxiliaries to address the main problem of using uniflow cylinders in a locomotive.) Another class member received Lentz rotary poppet valve gear.
Others tried out the Dabeg feedwater heater (2163), the ACFI water treatment system (2206 and 728), and two tested a trailing-truck booster. A heading photograph in the Railway Wonders show the setup. Replacing the single-axle trailing truck was a bogie pivoting under the cab that placed the rear axle under the front of the tender. A two-cylinder booster engine turned the rear axle. The other two tender axles also rode in a bogie. RW called it a "temporarily articulated" arrangement and commented that the wheel arrangement couldn't "be described by the standard system." [Maybe 2-4-2+0-2-0?
At least 14 survived to be included in the BR stud in 1948, but these were retired soon after.
Data from Ahrons (1927) and "New 'Atlantic' Locomotive, NER," The Locomotive Magazine, Vol IX (19 December 1903), p. 349.
A Wilson Worsdell design with larger than usual cylinders, but smaller grate. 10" piston valves were fitted inside the frames.
The data suggest a nicely balanced blend of power and economy. The report from LM noted that this class was "one of the largest and most powerful machines so far designed and built in this country for passenger servicet". Its bulk "...closely approximat[es] the extreme limits possible with the British loading gauge for a locomotive of ordinary outline." A side effect of this encroachment was to limit the driver's forward vision.
Superheated in 1914 using a boiler that was interchangeable with the Class Z locomotives; see Locobase 1495 for specifications. Later classed on the LNER as the C6. The generous boiler dimensions probably help to account for the durability of this class; the last of these weren't retired until 1948.
According to [] (visited November 2002), the C6 designation included 10 V/09s that were built in 1909 to a modified design. The cylinders shrank 1/2" to 19 1/2" diameter and the running plate and splashers were altered, too.
Data from "Three Cylinder 4-4-2 Locomotives, North Eastern Railway", The Locomotive Magazine, Volume XVII (15 November 1911), p. 243; "Express Passenger Locomotive for the North Eastern Railway, Atlantic Type," Railway and Locomotive Engineering, Vol XXV, No 2 (February 1912), p. 43; and "Railway Developments in Europe," Railway World (12 May 1911), p. 372.
Vincent Raven built twenty engines in this year, 10 as Z without superheaters, 10 as Z1 with superheaters. The order went to North British of Glasgow because the railway's shops had no openings on the production line.
These Zs had three cylinders and 7 1/2 " (191 mm)diameter piston valve chambers cast in one piece. Max cutoff was 65% and "notch 1" cut steam off at 15% of stroke. LM reports that the Zs were "urgently required to deal with the ever-increasing East Coast passenter traffic between York, Newcastle, and Edinburgh. A later report in American Engineer said that the class had been "very successful in handling trains of from 300 to 500 tons behind the tender at average speeds of 53 miles per hour."
The Zs wer.e superheated in 1914-1915 and all of these Atlantics were then called the Z1 class ( (Locobase 1495)
Principal Dimensions by Steve Llanso of Middle Run Media | |||||
---|---|---|---|---|---|
Class | 4CC | 4CC -- superheated / C8 | Class Z1/LNER C7 | V | Z |
Locobase ID | 2275 | 3530 | 1495 | 2290 | 1494 |
Railroad | North Eastern | North Eastern | North Eastern | North Eastern | North Eastern |
Country | Great Britain | Great Britain | Great Britain | Great Britain | Great Britain |
Whyte | 4-4-2 | 4-4-2 | 4-4-2 | 4-4-2 | 4-4-2 |
Number in Class | 2 | 2 | 50 | 10 | 10 |
Road Numbers | 730 | 730-731 | 722, 727-729. 732-737 | 532 | 706, 709-710, 714, 716-721 |
Gauge | Std | Std | Std | Std | Std |
Number Built | 2 | 40 | 10 | 10 | |
Builder | Gateshead | North British | North Eastern | North British | |
Year | 1906 | 1915 | 1911 | 1903 | 1911 |
Valve Gear | Stephenson | Stephenson or Walsch | Stephenson | Stephenson | |
Locomotive Length and Weight | |||||
Driver Wheelbase (ft / m) | 7.50 / 2.29 | 7.50 / 2.29 | 7.58 / 2.31 | 7.59 / 2.31 | 7.58 / 2.31 |
Engine Wheelbase (ft / m) | 28.75 / 8.76 | 28.75 / 8.76 | 29.50 / 8.99 | 28 / 8.53 | 29.50 / 8.99 |
Ratio of driving wheelbase to overall engine wheelbase | 0.26 | 0.26 | 0.26 | 0.27 | 0.26 |
Overall Wheelbase (engine & tender) (ft / m) | 52.81 / 16.10 | ||||
Axle Loading (Maximum Weight per Axle) (lbs / kg) | 44,800 / 20,321 | 44,464 / 20,169 | |||
Weight on Drivers (lbs / kg) | 87,696 / 39,778 | 87,696 / 39,778 | 98,560 / 44,706 | 87,382 / 39,636 | 88,704 / 40,236 |
Engine Weight (lbs / kg) | 164,864 / 74,781 | 164,864 / 74,781 | 172,480 / 78,236 | 161,280 / 73,155 | 171,808 / 77,931 |
Tender Loaded Weight (lbs / kg) | 94,080 / 42,674 | 101,472 / 46,027 | 97,440 | 100,800 | |
Total Engine and Tender Weight (lbs / kg) | 258,944 / 117,455 | 273,952 / 124,263 | 258,720 | 272,608 | |
Tender Water Capacity (gals / ML) | 4950 / 18.75 | 4950 | 4950 / 18.75 | ||
Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT) | 5.50 / 5 | 5.50 | 5.50 / 5 | ||
Minimum weight of rail (calculated) (lb/yd / kg/m) | 73 / 36.50 | 73 / 36.50 | 82 / 41 | 73 / 36.50 | 74 / 37 |
Geometry Relating to Tractive Effort | |||||
Driver Diameter (in / mm) | 85.50 / 2172 | 85.50 / 2172 | 82 / 2083 | 82 / 2083 | 82 / 2083 |
Boiler Pressure (psi / kPa) | 225 / 1550 | 225 / 1550 | 175 / 1210 | 200 / 1380 | 187 / 1290 |
High Pressure Cylinders (dia x stroke) (in / mm) | 14.5" x 26" / 368x660 | 14.5" x 26" / 368x660 | 16.5" x 26" / 419x660 (3) | 20" x 28" / 508x711 | 15.5" x 26" / 394x660 (3) |
Low Pressure Cylinders (dia x stroke) (in / mm) | 22" x 26" / 559x660 | 22" x 26" / 559x660 | |||
Tractive Effort (lbs / kg) | 17,049 / 7733.31 | 17,049 / 7733.31 | 19,261 / 8736.65 | 23,220 / 10532.43 | 18,162 / 8238.15 |
Factor of Adhesion (Weight on Drivers/Tractive Effort) | 5.14 | 5.14 | 5.12 | 3.76 | 4.88 |
Heating Ability | |||||
Tubes (number - dia) (in / mm) | 242 - 2" / 51 | 124 - 2" / 51 | 90 - 2" / 51 | 254 - 2" / 51 | 254 - 2" / 51 |
Flues (number - dia) (in / mm) | 18 - 5.25" / 133 | 24 - 5" / 127 | |||
Flue/Tube length (ft / m) | 14.60 / 4.45 | 15 / 4.57 | 16.22 / 4.94 | 16.25 | |
Firebox Area (sq ft / m2) | 180 / 16.73 | 180 / 16.73 | 185 / 17.19 | 180 / 16.73 | 180 / 17.19 |
Grate Area (sq ft / m2) | 29 / 2.70 | 29 / 2.70 | 27 / 2.51 | 27 / 2.51 | 27 / 2.51 |
Evaporative Heating Surface (sq ft / m2) | 2096 / 194.80 | 1525 / 141.73 | 1483 / 137.78 | 2456 / 228.25 | 2340 / 217.30 |
Superheating Surface (sq ft / m2) | 368 / 34.20 | 392 / 36.42 | |||
Combined Heating Surface (sq ft / m2) | 2096 / 194.80 | 1893 / 175.93 | 1875 / 174.20 | 2456 / 228.25 | 2340 / 217.30 |
Evaporative Heating Surface/Cylinder Volume | 421.80 | 306.89 | 153.65 | 241.23 | 274.73 |
Computations Relating to Power Output (More Information) | |||||
Robert LeMassena's Power Computation | 6525 | 6525 | 4725 | 5400 | 5049 |
Same as above plus superheater percentage | 6525 | 7765 | 5717 | 5400 | 5049 |
Same as above but substitute firebox area for grate area | 40,500 | 48,195 | 39,174 | 36,000 | 33,660 |
Power L1 | 8397 | 16,080 | 14,709 | 9010 | 9722 |
Power MT | 422.19 | 808.48 | 658.03 | 454.64 | 483.25 |