The CNJ's first Atlantic bucked the trend of camelback Atlantics then coming into use on the anthracite roads against which the railroad competed. Instead of a compound steam system, the CNJ adopted a simple-expansion layout. Tube diameter fell between the more common 1 1/2" and 2 or 2 1/4" as well.
In May 1905, the CNJ rebuilt this engine with 18" cylinders and in January 1912 mounted 79" drivers. 503 was scrapped in November 1926.
As with almost all Vauclain compounds operated in the USA, these Atlantics were rebuilt with simple-expansion cylinders. The conversion to 19" cylinders came in 1904 (5) and 1905 (1 - 585). Four years later, the CNJ fitted 79" drivers on the class, at which point the railroad designated them class P3.
All but one underwent one more modification when the shops increased cylinder size to 20 1/2"; this occurred over several years beginning in 1914 and ending in 1924. All were reclassified P4s, which suggests that part of the upgrade featured the addtion of a superheater.
By that time, 582, which received its larger cylinders in 1914, had been totalled in a March 1920 wreck. The others were all scrapped in 1928-1929.
This set of camelback Atlantics was smaller and lighter than the Brooks sextet that had appeared a year earlier (Locobase 5331). In 1909-1910 the three were rebuilt with 79" drivers, but as they lacked the sheer size and grate of the P-6s, they were not superheated.
574 was scrapped first in June 1928, with 572 following a month later, and 573 finishing the class in June 1930.
Builder info from B.Rumary, 25 Kingscombe, Gurney Slade, Radstock, BA3 4TH, ENGLAND and Jeremy Lambert as supplied by Allen Stanley in March 2004. Works #3951-3953 in August 1901 and numbered 588-590, renumbered 591-593 soon thereafter. Locoba e Cannot tell about the other two.
http://www.insighting.co.uk/homauchchunk/steam_class.htm for photos and further comments.
Locobase 5331 shows the sextet of Atlantics as they entered service in 1901. Unlike many of the other American railroads that operated 4-4-2s or Camelbacks, the CNJ held onto their doubly unusual P-6s until the end of steam. But the engines were quite different after a substantial makeover that included increasing piston diameter by 1 1/2" in cylinders supplied by 12" piston valves and reducing the driver diameter by 6 inches. At the same time, adhesion weight went up by more than 15 tons to handle the higher tractive effort. A reconfigured boiler substituted 24 flues (and their superheater elements) for 155 small tubes. Finally, the tender held more water and coal and weighed almost 15 tons more than its older counterpart.
|Specifications by Steve Llanso of Sweat House Media|
|Class||456 / P1||582 / P3a||P-1a||P-6||P-6 superheated|
|Railroad||Central RR of New Jersey||Central RR of New Jersey||Central RR of New Jersey||Central RR of New Jersey||Central RR of New Jersey|
|Number in Class||1||6||3||6||6|
|Road Numbers||456 / 573 / 570||582-587||597-599 / 573-574||590-595||590-595|
|Builder||Burnham, Williams & Co||Burnham, Williams & Co||Burnham, Williams & Co||Brooks||CNJ|
|Locomotive Length and Weight|
|Driver Wheelbase (ft)||7.25||7.25||7.25||7.67||7.67|
|Engine Wheelbase (ft)||26.42||26.58||26.42||29.83||29.92|
|Ratio of driving wheelbase to overall engine wheebase||0.27||0.27||0.27||0.26||0.26|
|Overall Wheelbase (engine & tender) (ft)||53.17||53.17||53.67||58.54|
|Axle Loading (Maximum Weight per Axle) (lbs)|
|Weight on Drivers (lbs)||80,000||88,000||84,100||99,400||127,800|
|Engine Weight (lbs)||141,000||167,000||151,000||191,000||215,700|
|Tender Loaded Weight (lbs)||100,000||99,000||124,000||153,800|
|Total Engine and Tender Weight (lbs)||267,000||250,000||315,000||369,500|
|Tender Water Capacity (gals)||3500||5000||5000||6000||7500|
|Tender Fuel Capacity (oil/coal) (gals/tons)||12||13|
|Minimum weight of rail (calculated) (lb/yd)||67||73||70||83||107|
|Geometry Relating to Tractive Effort|
|Driver Diameter (in)||84.50||84.25||84.50||85||79|
|Boiler Pressure (psi)||200||200||200||210||210|
|High Pressure Cylinders (dia x stroke) (in)||18.75" x 26"||14" x 26"||18" x 26"||20.5" x 26"||22" x 26"|
|Low Pressure Cylinders (dia x stroke) (in)||24" x 26"|
|Tractive Effort (lbs)||18,389||15,344||16,948||22,946||28,433|
|Factor of Adhesion (Weight on Drivers/Tractive Effort)||4.35||5.74||4.96||4.33||4.49|
|Firebox Area (sq ft)||189.80||185.37||170.70||174||173.90|
|Grate Area (sq ft)||76||76||73||82||81.63|
|Evaporative Heating Surface (sq ft)||1835||2669||2174||2967||2188|
|Superheating Surface (sq ft)||460|
|Combined Heating Surface (sq ft)||1835||2669||2174||2967||2648|
|Evaporative Heating Surface/Cylinder Volume||220.84||576.16||283.90||298.72||191.27|
|Computations Relating to Power Output (More Information)|
|Robert LeMassena's Power Computation||15,200||15,200||14,600||17,220||17,142|
|Same as above plus superheater percentage||15,200||15,200||14,600||17,220||20,056|
|Same as above but substitute firebox area for grate area||37,960||37,074||34,140||36,540||42,727|