Seatrax Inc. Offshore Cranes Hoisting Draw-Works Data

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Fail-Safe Hoist Features

These Seatrax hoists are individual hydraulic motor driven units, which consist of the following major components:

High speed, fixed displacement, low torque hydraulic motor either of the gear, vane, or axial piston type, depending on crane and hoist models.

"Fail-safe" spring-applied, pressure-released dynamic brake valve direct connected to the inlet port of each hydraulic motor.

Gear reduction connecting the hydraulic motor to the drum shaft.

One-piece, solid drum shaft supported on both ends by anti-friction bearings, which drives the hoist drum through a hardened spline connection.

"Fail-safe" spring-applied, pressure-released static parking brake acts directly on the hoist drum.

...more

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Seatrax Hoist Inspection Requirements

Disassembly and internal inspection of the gear reducer components during Annual Inspections or other routine inspection intervals is NOT REQUIRED and is NOT RECOMMENDED.

Disassembly and internal inspection of the gear reducer components is only required if any of the following conditions are encountered during operation:

Strange or unusual noises

Unusual or sudden increase in the surface temperature of the gear housing

Substantial leakage of gear lubricant

Unusual amounts of metal or other contaminants in the gear lubricant

...more

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Why Seatrax Doesn't Use "Braden"-Type Winches

Seatrax does not use "Braden"-type hoists or other hoists of the "works in the drum" design. Instead, we make our own hoists, which are superior to the "Braden"-type hoists in this application. Our reasons for this are as follows:

"Braden"-type hoists have the planetary reduction gearing and static brake mechanisms mounted inside the drum barrel. This means that a "Braden"-type hoist must be removed from its mount and completely dissembled to inspect or replace the gearing and other load transmitting components.

Seatrax hoists have the reduction gearing mounted externally. All gearing and load-transmitting components of a Seatrax hoist can be disassembled and inspected without removing the hoist from its mount or removing the wire rope or drum from the hoist. It is never necessary to remove a Seatrax hoist from its mount in order to perform any inspection or component replacement....more

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Closed vs. Open Loop Configurations for Hoisting Applications

Seatrax uses an open loop configuration for all of its variable displacement hydraulic systems, which are used for hoisting applications. These systems utilize the same type of variable displacement, high pressure, piston pumps that are used on the more familiar European closed loop systems. Seatrax's open loop configuration for this same type of equipment provides equal or better infinitely variable speed control in both directions of movement and addresses well-known safety and maintenance concerns that continue to be a problem with the closed loop system configuration...more.

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Lifting of Personnel with Seatrax Cranes and Hoists

All Seatrax offshore cranes carry a nameplate with the API 2C monogram and are approved by Seatrax for the purpose of lifting personnel when operated and maintained in accordance with the latest edition of API Recommended Practice 2D. These cranes are designed and manufactured in compliance with API Specification 2C...more.

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Minimum Required Hook Speeds at Various Sea Conditions

Click here to download a PDF of this chart.

All technical papers are available in PDF and compressed formats (Recommended for Mac/Safari users).
back to top	Fail-Safe Hoist Features These Seatrax hoists are individual hydraulic motor driven units, which consist of the following major components: High speed, fixed displacement, low torque hydraulic motor either of the gear, vane, or axial piston type, depending on crane and hoist models. "Fail-safe" spring-applied, pressure-released dynamic brake valve direct connected to the inlet port of each hydraulic motor. Gear reduction connecting the hydraulic motor to the drum shaft. One-piece, solid drum shaft supported on both ends by anti-friction bearings, which drives the hoist drum through a hardened spline connection. "Fail-safe" spring-applied, pressure-released static parking brake acts directly on the hoist drum. ...more
back to top	Seatrax Hoist Inspection Requirements Disassembly and internal inspection of the gear reducer components during Annual Inspections or other routine inspection intervals is NOT REQUIRED and is NOT RECOMMENDED. Disassembly and internal inspection of the gear reducer components is only required if any of the following conditions are encountered during operation: Strange or unusual noises Unusual or sudden increase in the surface temperature of the gear housing Substantial leakage of gear lubricant Unusual amounts of metal or other contaminants in the gear lubricant ...more
back to top	Why Seatrax Doesn't Use "Braden"-Type Winches Seatrax does not use "Braden"-type hoists or other hoists of the "works in the drum" design. Instead, we make our own hoists, which are superior to the "Braden"-type hoists in this application. Our reasons for this are as follows: "Braden"-type hoists have the planetary reduction gearing and static brake mechanisms mounted inside the drum barrel. This means that a "Braden"-type hoist must be removed from its mount and completely dissembled to inspect or replace the gearing and other load transmitting components. Seatrax hoists have the reduction gearing mounted externally. All gearing and load-transmitting components of a Seatrax hoist can be disassembled and inspected without removing the hoist from its mount or removing the wire rope or drum from the hoist. It is never necessary to remove a Seatrax hoist from its mount in order to perform any inspection or component replacement....more
back to top	Closed vs. Open Loop Configurations for Hoisting Applications Seatrax uses an open loop configuration for all of its variable displacement hydraulic systems, which are used for hoisting applications. These systems utilize the same type of variable displacement, high pressure, piston pumps that are used on the more familiar European closed loop systems. Seatrax's open loop configuration for this same type of equipment provides equal or better infinitely variable speed control in both directions of movement and addresses well-known safety and maintenance concerns that continue to be a problem with the closed loop system configuration...more.
back to top	Lifting of Personnel with Seatrax Cranes and Hoists All Seatrax offshore cranes carry a nameplate with the API 2C monogram and are approved by Seatrax for the purpose of lifting personnel when operated and maintained in accordance with the latest edition of API Recommended Practice 2D. These cranes are designed and manufactured in compliance with API Specification 2C...more.
back to top	Minimum Required Hook Speeds at Various Sea Conditions Click here to download a PDF of this chart.

Hoisting Data