National Oilwell 110-UE Drawworks

National Oilwell 110-UE Drawworks – Specifications

Manufacturer: National Oilwell
Model: 110-UE
Type: Mechanical Drawworks
Application: Medium drilling & workover rigs

General Description

The National 110-UE is a heavier-duty upgrade from the 80-series drawworks, designed for medium-depth drilling and heavier hoisting loads. The “UE” (Unitized Equipment) configuration integrates improved gearing, braking, and frame strength for higher reliability and smoother operation.

Mechanical Specifications

• Drum Diameter: ~27–28 in

• Drum Length: ~42 in

• Drum Type: Single grooved drum

• Main Shaft Diameter: ~7 in

• Frame: Heavy cast steel

• Design: Enclosed gearing, unitized frame

Power & Drive

• Rated Input Power:

  • 450–600 HP (configuration dependent)

• Drive Type:

  • Compound chain drive or direct drive

• Clutches:

  • Air-operated friction clutches

Hoisting Capacity

• Fast Line Pull: ~45,000 – 55,000 lb

• Maximum Hook Load: ~250,000 – 300,000 lb
  (depends on drilling line size and number of lines strung)

• Drilling Line Size:

  • 1 in – 1⅛ in wire rope (typical)

Braking System

• Primary Brake:

  • Mechanical band brake

• Auxiliary Brake:

  • Hydromatic brake (very common)

• Emergency Brake:

  • Manual band brake

Gearbox & Speeds

• Number of Speeds:

  • 4 forward + reverse

• Gear Type:

  • Hardened spur/helical gears

• Lubrication:

  • Pressure or splash lubrication (varies by build year)

Typical Rig Pairings

• CAT 3406 / C15 / C18

• Detroit Series 60

• National 7-P-50, 8-P-80, or similar mud pumps

• Mechanical or SCR land rigs (1,500–5,000 ft typical)