Cab Forward Facts and Trivia

Cab Markings

What did those Cab Forward cab markings mean?

24 24 AC-4 AC63            475 SF 32

AC-4	Class designation
AC63	Articulated Consolidation, 63 inch drivers
24 24	Cylinder diameter (front and rear) in inches
32	Piston stroke in inches
475	Weight on drivers in thousands of pounds
SF	Superheated, Feedwater heater

The Monkey Deck

Monkey Deck

The Southern Pacific Cab Forwards had a platform immediately following the smokebox of the locomotive (as shown in the figure to the right). This platform was called the "monkey deck. Smoke boxes were often stained with rust from boiler water and boiler water treatment chemicals. Because of its proximity to the stacks, the monkey deck was often stained with rust from boiler water too. Occasionally articulateds would spew hot water and mud from their stacks. Most railroad employees were aware of this fact. However, many hoboes thought the monkey deck was a good place to ride. After passing through tunnels or snow sheds, hoboes riding the deck were either scalded or asphyxiated depending upon how the locomotive was performing. The monkey deck was not a good place to ride on Cab Forward locomotives.

Southern Pacific Yellowstones

Not all Southern Pacific articulateds were Cab Forwards. Class AC-9 was made up of 12 Lima built Superpower, coal burning Yellowstones (2-8-8-4). They had the same tractive effort of the Cab Forwards. They were numbered 3800 - 3811 and were used in the Southwest.

Cab Forward Classes

Class	Locomotive Number	Wheel Arrangement	Driver Diameter	Cylinders	Steam Pressure	Tractive Effort	Horse Power
MC-1	4000-4001	2-8-8-2	57	26x40x30	200	85,040	4000
MC-2	4002-4016	2-8-8-2	57	26x40x30	200	85,040	4000
AC-1	4000-4016	2-8-8-2	57	22x22x30	210	90,940	4350
MC-4	4017-4028	2-8-8-2	57	26x40x30	200	85,040	4000
AC-2	4017-4028	2-8-8-2	57	22x22x30	210	90,940	4350
MC-6	4029-4048	2-8-8-2	57	26x40x30	200	85,040	4000
AC-3	4029-4048	2-8-8-2	57	22x22x30	210	90,940	4350
MM-2	4200-4211	4-6-6-2	63	25x38x28	200	65,900	3000
AM-2	3900-3911	4-6-6-2	63	22x22x28	210	76,800	3450
AC-4	4100-4109	4-8-8-2	63	24x24x32	235	116,900	5640
AC-5	4110-4125	4-8-8-2	63	24x24x32	235	116,900	5640
AC-6	4126-4150	4-8-8-2	63	24x24x32	250	124,300	6000
AC-7	4151-4176	4-8-8-2	63	24x24x32	250	124,300	6000
AC-8	4177-4204	4-8-8-2	63	24x24x32	250	124,300	6000
AC-9*	3800-3811	2-8-8-4	63	24x24x32	250	124,300	6000
AC-10	4205-4244	4-8-8-2	63	24x24x32	250	124,300	6000
AC-11	4245-4274	4-8-8-2	63	24x24x32	250	124,300	6000
AC-12	4275-4294	4-8-8-2	63	24x24x32	250	124,300	6000

NOTE: Class AC-9 were Yellowstones (not Cab Forwards)

The Last Cab Forwards

• The last Cab Forward in revenue service was 4-8-8-2 4211 which hauled freight from Oakland to Davis and then to Roseville with only a caboose on November 30th, 1956.
• In November, 1957 4274 was brought out of retirement to make the last run of a Cab Forward over Donner Pass from Sacramento to Sparks and back.
• Cab Forward 4180, stored at Watsonville Junction, was hauled to the shops for painting and preservation. On the way to a park in Oakland, inadequate support timbers during a city street move resulted in a disaster and the scrapping of 4180. Date unknown. Source Gunnar Henrioulle.
• In 1960 the last Cab Forward to be scrapped was AC-10 4243.
• On May 7, 1981 AC-12 4294 was designated a National Historic Mechanical Engineering Landmark.

Web Pages

• Other Cab-Forward Locomotives (SkyRocket.de)
• Other Cab-Forward Locomotives (Douglas-self.com)
• Southern Pacific Cab-Forward's Steam Roster
• Cab Forward AutoCad Drawing

Reference

• Cab Forward 4294 (Sold by Aeronaut Books and Amazon)