Overview
The Gibson Model I is a row-crop farm tractor manufactured in Longmont, Colorado, between 1948 and 1952. It features a Hercules 3.9L six-cylinder gasoline engine and a transmission with four forward and one reverse gear. Nebraska Tractor Test 408 documented a maximum belt power of 41.03 hp and a maximum drawbar pull of 4676 lbs.
Ideal Applications
Tested Power Performance:
Nebraska Test 408 recorded a maximum belt power of 41.03 hp and a maximum drawbar output of 29.1 hp using the second and third gear test configurations.
Mechanical and Drive Specifications:
The tractor is equipped with a live 540 RPM rear PTO, mechanical band brakes, and a four-speed gear transmission with a 254mm dry disc clutch.
Chassis and Front-End Variants:
Built on a 94-inch wheelbase with 25 inches of ground clearance, the model was offered in tricycle-front, adjustable wide-front, and standard front configurations.
Production
| Description | Row-Crop tractor / Built in Longmont, Colorado, USA |
|---|---|
| Manufacturer | Gibson |
Engine
| Engine type | Hercules 3.9L 6-cyl gasoline |
|---|---|
| Fuel tank | 20 gal (75.7 L) |
| Air cleaner | oil bath |
| Bore/Stroke | 3.4375x4.125 inches (87 x 105 mm) |
| Compression | 6.71:1 |
| Coolant capacity | 17 qts (16.1 L) |
| Description | Hercules ZXD / gasoline / 6-cylinder / liquid-cooled |
| Displacement | 236.7 ci (3.9 L) |
| Rated RPM | 1800 |
| Starter volts | 6 |
| Belt (tested) | 41.03 hp (30.6 kW) |
| Drawbar (tested) | 29.1 hp (21.7 kW) |
| Plows | 2-3 |
| PTO (tested) | 36.82 hp (27.5 kW) |
Transmission
| Clutch | 254mm dry disc |
|---|---|
| Gears | 4 forward and 1 reverse |
| Transmission type | 4-speed gear |
| Type | gear |
Mechanical
| Cab | Open operator station. |
|---|---|
| Description | Manual steering / Mechanical band brakes |
| Drive type | Two-wheel drive |
| Final drives | bull gear |
PTO
| Rear PTO | live |
|---|---|
| Rear PTO Type | 540 (1.375) |
Dimensions & Tires
| Ground clearance | 25 inches (63 cm) |
|---|---|
| Height | 67 inches (170 cm) |
| Length | 127.25 inches (323 cm) |
| Rear tread | 49 to 90 inches (124 to 228 cm) |
| Wheelbase | 94 inches (238 cm) |
| Front tire | 5.50-16 |
| Rear tire | 10-38 |
| Weight | 4000 to 4512 pounds |
| Wheelbase | 94 inches (238 cm) |
| Ag front | 5.50-16 |
| Ag rear | 10-38 / 11-38 |
Belt Pulley
| Diameter | 9.2 inches (23 cm) |
|---|---|
| RPM | 1487 |
| Speed | 3539 ft/min (1078.69 meters/min) |
| Width | 7.5 inches (19 cm) |
Gibson I Weight
| Ballasted | 7495 lbs (3399 kg) |
|---|---|
| Operating | 4512 lbs (2046 kg) |
| Shipping | 4000 lbs (1814 kg) |
Nebraska Tractor Test 408
| Belt fuel use (max) | 4.2 gal/hour (15.9 l/hour) |
|---|---|
| Belt power (max) | 41.03 hp (30.6 kW) |
| Description | Gasoline 4-speed 2WDMay 8 - 12, 1949Link: Nebraska Tractor Test 408 file / PTO performance / Drawbar performance / Gear 3 used for power test. / Gear 2 used for pull test. |
| Fuel use | 3.6 gal/hour (13.6 l/hour) / 3.2 gal/hour (12.1 l/hour) |
| Max power | 29.1 hp (21.7 kW) |
| Max pull | 4676 lbs (2121 kg) |
| Power at rated engine speed | 36.82 hp (27.5 kW) |
References
| Description | Gibson Tractors - Durability, lower operating costs, plus extra power. published in 1948 |
|---|
Variants
| I | tricycle-front |
|---|---|
| IFA | adjustable wide-front |
| IFS | standard front |