All technical papers are available in PDF and compressed formats
(Recommended for Mac/Safari users).
Method of Support and Slew Bearing Arrangement
All Seatrax cranes are based on the well-proven kingpost concept. This basic design consists of a stationary or fixed kingpost and a revolving superstructure, which fits over and revolves round the stationary post. The boom, machinery house, operators cabin, hoists and slewing machinery are all fitted to the revolving superstructure...more.
API Specification 2C Kingpost/Pedestal Design and Fatigue Considerations
Since 1983, API Specification 2C requires the use of conservative allowable stresses for kingpost or pedestal design. The intent has is to ensure operating stresses, with respect to safe working load, are such that the API default 25,000 cycle design criteria will be automatically met without further consideration.
API Specification 2C - Allowable Kingpost/Pedestals Stress
To implement this Specification, API kingposts and pedestals have additional factors of increase of 1.33 and 1.5 added to the safe working load (SWL). This factored load is then used in conjunction with AISC allowable stresses. The nominal AISC allowable bending stress for round tubes is 0.66 * Fy. This equates to a factor of safety of 1.5. When the factors of increase are applied, the resulting factor of safety relative to safe working load is approximately (1.33 * 1.5 * 1.5) = 3.0 with respect to yield. The allowable stress is approximately 33% of yield...more.
Patented API 2C Anti-Blocking System
For many years, Seatrax has used its innovative solution to remedy crane operations accidents caused by the unintentional contact between the hook block (or ball) and the boom point, often referred to as two-blocking.
One type of two-blocking, often described as “booming down into the block,” occurs on most cranes because of the location of the hoist drum, which is typically mounted on the revolving superstructure. (See Figure 1). Through this arrangement, the distance between the hoist drum and the boom tip sheaves increases as the boom is lowered, causing the lower block (hook block) to move closer to the upper block (boom tip sheaves)...more.
Anti-Two-Blocking System Comparison
Two-blocking may also occur when crane operators over hoist the hook block (or auxiliary hook), regardless of the position or angle of the boom. Seatrax, through straightforward geometry, easily solves this problem. This simple system takes advantage of the hydraulic motors Seatrax cranes use to power their hoists...more.
Drilling Duty vs. Production Installations
The Seatrax marine offshore crane product line consists of a wide range of standard crane structures that can be equipped with several types of standard machinery packages. The crane structure size is determined from the lifting capacity/radius requirements. The machinery packages are determined by the intended service on the offshore installation.
The following pictorial displays the machinery arrangement differences between structurally identical cranes configured either for typical fixed platform support or drilling duty and floating installations...more.
Seatrax Drilling Duty vs. Typical Production Duty Cranes
Seatrax has primarily built deepwater drilling cranes for many years. In the deepwater drilling environment, the cranes typically run 24/7 under extreme dynamic conditions.
Drilling crane owners and operators are most concerned with costly crane maintenance and safety. The primary reason for these concerns are the shortcomings of the typical platform crane, being modified and adapted for the drilling environment. These shortcomings include rotation bearing and mounting bolt maintenance and failures, very small winches requiring periodic replacement or tear-down for inspection, inadequate winch breaking, anti-two blocking, wire rope maintenance, and the overall corrosion resistance of the structure and equipment...more.
Comparison of Seatrax Kingpost-Type Cranes to Conventional Box Boom Cranes
This technical paper discusses the advantages of Seatrax kingpost-type cranes over conventional box boom cranes...more.
Seatrax Boom Suspension Systems
Seatrax offers two types of boom suspension systems. This includes pendant and bridle as well as continuously reeved.
The boom suspension system is the collection of wire ropes, sheaves, shafts, blocks and other rigging components used to support the boom.
The pendant and bridle system consists of...more.
Seatrax Boom Suspension Systems
Seatrax offers two types of boom suspension systems. This includes pendant and bridle as well as continuously reeved.
The boom suspension system is the collection of wire ropes, sheaves, shafts, blocks and other rigging components used to support the boom.
The pendant and bridle system consists of...more.
 |
ABOUT SEATRAX | CONTACT US | CAREERS |
