Macdonald & Lawrence Timber Framing Ltd.

Prior to the Main Event that began on Friday, the Guild hosted a pre-conference workshop on cranes, led by Gord Macdonald and Steve Lawrence. Laura Brown sent us a report and photos of the workshop.

The history of raising timber frames with modern cranes is young; in contemporary construction, cranes are most often used for steel construction. Gordon and Steve shared their many tips, tricks, and techniques specific to rigging and lifting timber structures. Designed for folks familiar with raisings, the workshop contained "buckets" of information. The presentation was thorough, covering planning, engineering, center of gravity calculations (in a manner easily understood even by me).

Gord presented the intimidating reality of dealing with OSHA regulations in a very relaxed manner that made me feel that this four letter word is not one to run and hide from. He took us through samples of raising plans, rigging lists and tables, load charts, reference books, and online information, and emphasized the need to always keep communication open with your team from the planning stages through the actual raising. Steve covered sling types and methods, shackles, master links, hoists, spreader bars, man baskets, and boson's chairs. It was a full morning of information, but everyone was eager for more.

Then we got to go outside and put theory into action. Classen Crane Service provided a brand new 90-ton crane for us. Under Gord's direction, we were shown how to ask the right questions and better understand the job from the crane operator's point of view. He emphasized communication, communication, communication. Always let people know what you need and then listen to their needs. In the crane world, vocal communication can be a problem (because of the noise level), so hand signals or radios are essential.

After several exercises with Gord, Steve took us though two fancier lifts. A large bent was assembled with truck strap connections; Steve rigged the bent to be lifted with two spreader bars to demonstrate tandem lift. The bent was rigged so that there was very little strain on the truck strap joinery; Steve directed the crane operator to roll it to 45 degrees. The bent gracefully lifted off the bunks with no evidence of twisting or strain, and when high enough, it gently bowed to the crowd until it was returned to earth. Using center of gravity calculations and with the aid of two spreader bars, Steve knew exactly where to rig the straps at the four points to raise the bent as though it was weightless.

Next he moved to a more complicated element, an asymmetrical frame with a long vertical timber on one side. The calculations were a bit more complicated for center of gravity points, but Steve had it all figured out ahead of time and had rigged the frame ready for the lift. This lift was an example of a rolling pick and a transfer pick in that there was a snatch block and wire rope which allowed the pick points to roll as the load shifted when the frame lifted. The very lopsided frame began its ascent in a slow and out-of-balance manner, but as the wire rope slid through the sheave, the single-legged frame became vertical and stood tall on its one post, held aloft by the crane to the cheers of the group. This pick was used in the Salem project last spring.

Safety must be front and center in Guild projects and in the information we bring to timber framing. As we develop more complicated designs, we also must deal with the process of assembling these grand structures safely and efficiently. Learning and adjusting crane practices for the specific needs of timber framing is the task of the present day timber framer, and the Guild is helping to lead the way with workshops such as this.