National 610 Drawworks

National Oilwell 610 Drawworks – Specifications

Manufacturer: National Oilwell
Model: 610
Type: Mechanical Drawworks
Application: Land drilling rigs (workover to medium drilling)

General Description

The National 610 Drawworks is a compact, heavy-duty mechanical drawworks designed for medium-depth land rigs. It is widely used due to its reliability, simple mechanical design, and compatibility with diesel-electric or mechanical power systems.

Mechanical Specifications

• Drum Diameter: 30 in

• Drum Length: 42 in

• Drum Construction: Single drum, grooved

• Main Shaft Diameter: ~8 in

• Brake Type:

  • Hydromatic brake (National 750 or similar)

  • Band brake (mechanical)

Power & Drive

• Rated Input Power:

  • Up to 600 HP (varies by gearing and brake configuration)

• Typical Drive:

  • Chain drive or compound drive

  • Diesel or diesel-electric input

• Clutches:

  • Air-operated friction clutches

Hoisting Capacity

• Fast Line Pull: ~60,000 – 70,000 lb

• Maximum Hook Load: ~300,000 lb (depending on line size and reeving)

• Drilling Line Size:

  • 1 in – 1⅛ in wire rope (typical)

Braking System

• Primary Brake: Mechanical band brake

• Auxiliary Brake:

  • Hydromatic brake (water-cooled)

• Emergency Brake: Manual band brake