STANDARD HANDBOOK OF PETROLEUM & NATURAL GAS ...

Derricks and Portable Masts 507
The manufacturer shall establish the reduced rated static hook loads for the
same conditions under which the maximum rated static hook loads apply, but
with the addition of the pipe-setback and sucker-rod loadings. The reduced rated
static hook loads shall be expressed as percentages of the maximum rated static
hook loads. Thus, the portable mast ratings in Standard 4D include a safety
factor of 2 to allow for wind and impact loads, and require the manufacturer
to specify further capacity reductions due to setback.
The policy of Standard 4D, that the manufacturer specify the structure load
capacity for various loading configurations, has been applied in detail in
Standards 4E (superseded by Standard 4F) and 4F. Standard 4F calls for detailed
capacity ratings that allow the user to look up the rating for a specific loading
configuration. These required ratings are as follows.
Standard Ratings
Each structure shall be rated for the following applicable loading conditions.
The structures shall be designed to meet or exceed these conditions in
accordance with the applicable specifications set forth herein. The following
ratings do not include any allowance for impact. Acceleration, impact, setback,
and wind loads will reduce the rated static hook load capacity.
Derrlck-Stationary
Base
1. Maximum rated static hook load for a specified number of lines to the
traveling block.
2. Maximum rated wind velocity (knots) without pipe setback.
3. Maximum rated wind velocity (knots) with full pipe setback.
4. Maximum number of stands and size of pipe in full setback.
5. Maximum rated gin pole capacity.
6. Rated static hook load for wind velocities varying from zero to maximum
rated wind velocity with full rated setback and with maximum number of
lines to the traveling block.
Mast with Guy Lines
1. Maximum rated static hook load capacity for a specified number of lines
strung to the traveling block and the manufacturer’s specified guying.
2. Maximum rated wind velocity (knots) without pipe setback.
3. Maximum rated wind velocity (knots) with full pipe setback.
4. Maximum number of stands and size of pipe in full setback.
Mast wlthout Guy Lines
traveling block.
1. Maximum rated static hook load for a specified number of lines to the
2. Maximum rated wind velocity (knots) without pipe setback.
3. Maximum rated wind velocity (knots) with full pipe setback.
4. Maximum number of stands and size of pipe in full setback.
5. Rated static hook load for wind velocities varying from zero to maximum
rated wind velocity with full rated setback and with maximum number of
lines to the traveling block.