National OS-215 Dynamic Load Re-rating

ALATAS’ SERVICEENGINEERING
LOCATION  ASIA / GULF OF SUEZ
EQUIPMENT  JACK-UP PLATFORM DECK
BRAND / MODELNATIONAL NOV OS-215 HYDRAULIC PEDESTAL CRANE

INTRODUCTION:

Alatas Engineering and Design Services has conducted a re-rating study to create offboard SWLs for a client’s asset crane.

BACKGROUND:

The National OS-215 hydraulic pedestal crane has multiple parts of reeving ranging up to 10-Fall. Offboard lift curves require a minimum hoisting speed to ensure the crane can lift a load quickly enough for the required sea state. The client requested that a dynamic/offboard lifting load chart be created to assist in the day-to-day operations and versatility of the crane.

ALATAS SOLUTION:

Alatas Engineering and Design Services carried out detailed design load calculations and a mechanical system review to provide class- /code-approved dynamic operating SWL values.

JOB SCOPE:

  • Reviewing the crane’s operational data and hoisting capabilities:
  • Assessing the minimum required hoisting speed for dynamic offboard lifts under specific sea state conditions.
  • Determining the boom tip design loads using the manufacturer’s load charts, considering line pull and hoisting speeds.
  • Developing an onboard static load curve considering design loads, number of falls, and hoisting speed restrictions for main and whip hoists.
  • Constructing an offboard load curve for a designated sea state, typically SWH 2.5m, based on onboard design loads, number of falls, and hoisting speed limitations.
  • Compiling a re-rated load chart document incorporating onboard static and offboard dynamic Safe Working Load (SWL) curves, considering the number of falls, relevant design standards, and client specifications.
  • Providing a summary report outlining the methodology used for the re-rating review and offering recommendations based on the study findings.

2 / 2

Search

Share Article

Recent Posts

Scroll to Top