TD Equipment Inc. manufactured the only Top
Drive drilling system designed specifically to fit into a standard
double rig. The Top Drive drilling system was designed by Allan
R. Nelson Engineering (1997) Inc. who had negotiated a license agreement
with TD Equipment in the fall of 2004.
In the fall of 2005 an agreement was negotiated
with TD Equipment Inc. to rescind the license allowing it to be
issued to Farr Canada. Farr Canada is a substantially larger organization
with a worldwide network for sales and support, with the capability
to produce substantial revenue for the technology.