GB690526A - Improvements in or relating to a substructure for a mast - Google Patents

Abstract

690,526. Raising derrick masts. MOORE CORPORATION, L. C. May 28, 1951. No. 12448/51. Class 78 (iv). The -feet 18 (Fig. 2) of a derrick mast E assembled on a temporary support 17 are guided into engagement with shoes 10 on the substructure illustrated by a pair of parallel arms 20 pivoted to brackets 21 on the side frames A and B (Fig. 1) of the substructure and to brackets 23 on the front legs 16 of the mast when the feet are raised by a sling 24 which passes over a gin pole D. The arms 20 are then disconnected from the mast and are bolted to brackets 30 on a frame C mounted transversely on the tops of the side frames A and B and serving, when the mast has been raised by a line 26 which extends from the draw-works to the crown block, to secure a pipe setback support (not shown) mounted immediately in front of it on the side frames. The rotary table (not shown) is mounted on the frame C and is thus sufficiently high to leave room beneath for equipment for sealing the well casing should high pressure gas or liquid zones be encountered. The side frames A and B are detachably joined by cross members 1 forming a deck at such a height that equipment may readily be slid onto it from the platform of a. lorry. The shoes 10 also support the front legs 12 of the gin pole the longer rear legs of which are carried by shoes 11 and are reinforced by braces 14.