Oliver OC-12

Last Updated: July 2024

Overview

The Oliver OC-12 is a heavy-duty crawler tractor powered by a Hercules 6-cylinder liquid-cooled diesel engine with a displacement of 339 cubic inches, a bore of 4 inches, and a stroke of 4.5 inches. It produces a maximum power output of 57.93 horsepower at a rated speed of 1750 RPM. The tractor features a gear-driven transmission with 4 forward and 2 reverse gears, and a tracked chassis for enhanced traction and stability on rough terrain. With dimensions of 109.75 inches in length, 58 inches in width, and 66.5 inches in height, and an operating weight of 11,259 pounds, the OC-12 is a robust and capable machine. Additional features include a 12-inch belt pulley, an upholstered seat with sponge rubber and steel spring, contracting band brakes operated by steering levers, a variable speed centrifugal governor, a battery ignition system, and a 6-volt battery starting system.

Key Specifications

Category: Crawler

Power Output: 57.93

Transmission: Gear

Drive Type: Tracked

Operating Weight: 11259

Fuel Type: Diesel

Oliver OC-12 vs. Similar Tractors

Operating Weight

Average

Greater than 43% of similar tractors.

Technical Specifications

Engine

Manufacturer: Hercules
Model: -
Cooling Type: Liquid
Cylinder Orientation: -
Valve Configuration: -
Fuel Type: Diesel
Induction Type: Naturally Aspirated
Cylinders: 6
Displacement (ci): 339
Bore (in): 4.00
Stroke (in): 4.5
Rated RPM: 1750
Power Output (hp): 57.93

Transmission

Type: Gear
Forward Gears: 4
Reverse Gears: 2
Total Gears: -

Dimensions

Length (in): 109.75
Width (in): 58
Height (in): 66.5
Operating Weight (lb): 11259

Power Take-Off (PTO)

PTO Type: -
PTO Speed 1 (rpm): -
PTO Speed 2 (rpm): -
PTO Speed 3 (rpm): -

Miscellaneous

Chassis: Tracked
Drive Type: Tracked
Steering Type: Manual
Coolant Capacity (qts): Unknown
Front Tire Diameter (in): -
Front Tire Width (in): -
Rear Tire Diameter (in): -
Rear Tire Width (in): -
Front/Rear Rim Diameter (in): -
Tire Type: -
Manufacture - End Year: -
Hitch Type: -
Hitch Category: -
Hitch Position: -
Hitch Capacity (lb): -
Operator Station Type: Open
Starter Type: -
Brake Type: -
Hydraulic System Type: -

Test Results

Nebraska Tractor Test Laboratory - Test Date: June 15 to June 28, 1955

Maximum Power and Fuel Consumption

Maximum Belt Horsepower: 57.93 HP at 1750 rpm
Fuel Consumption at Maximum Power: 5.973 Gal/hr with a fuel efficiency of 10.27 Hp.hr/gal (0.636 lb/hp.hr)
Fuel Consumption at Operating Maximum Load: 5.195 Gal/hr with a fuel efficiency of 10.52 Hp.hr/gal (0.586 lb/hp.hr)

Drawbar Performance

Power at Rated Engine Speed (2nd Gear): 37.85 HP with a drawbar pull of 10399 lbs, a speed of 1.36 mph, and a wheel slip of 15.18%
Maximum Drawbar Horsepower (2nd Gear): 50.83 HP with a drawbar pull of 8403 lbs, a speed of 2.27 mph, and a wheel slip of 3.40%
Power at Higher Gear (4th Gear): 44.08 HP with a drawbar pull of 3161 lbs, a speed of 5.23 mph, and a wheel slip of 1.08%

Torque and Engine Performance

Maximum Torque: 371.9 lb-ft at 943 rpm
Torque Rise: Torque increases up to 364.9 lb-ft as engine speed decreases from 1750 to 1045 rpm

Vehicle Details

Total Weight: 11,259 lbs (with operator)
Engine Specifications: Hercules JXLD, 6 cylinder vertical, 339 cu in displacement, 4" x 4.375" bore and stroke, 6.25 to 1 compression ratio

Overall Efficiency

Fuel Consumption at Varying Loads (Average of 2 hours): 5.023 Gal/hr with a fuel efficiency of 10.27 Hp.hr/gal (0.600 lb/hp.hr)

NTTL.(1955).Nebraska OECD Tractor test 548 for Oliver OC-12 Diesel. Lincoln, NE: Nebraska Tractor Test Laboratory. Retrieved from https://digitalcommons.unl.edu/tractormuseumlit/529