from Amazon. It's designed to hold a can the diameter of a common soda or beer can
Two hours 40 minutes but it could have been 15 minutes less.
For the diehards that want more detail:
There is a lot of controversy, especially among people who have never observed the process, about the health hazards presented by the use of a galvanized can. It seems that they've heard about welding fume fever caused by breathing the fumes of welding galvanized materials. This process doesn't get nearly hot enough to cause gassing like that created in the welding process. While some sources suggest 700 degree temps in the can, I'll note that the string holding the wings survives and liquid remains in the can even though it starts out less than half full. Some individuals seem to think that any contact between galvanizing and potable products is a significant risk, simply forgetting or ignorant of the number of people whose homes were and in some cases still are plumbed with galvanized pipe. In this application, there shouldn't be any contact between the can and the turkey.
A very experienced dutch oven cooking individual who learned the technique from a gal that I taught has adapted the process to use a 60 quart aluminum stock pot which seems an elegant approach. I especially like the stand he fabricated although it would be too tall for my can. You can read his report online.
HowToLou posted a video of their technique on YouTube. They use a larger can, much more charcoal, a piece of steel rod for the stand, and no aluminum foil reflecting the heat outside the can. Others use a pan inside the can under the stand to avoid having the dripping run out under the can. While I've observed that technique, I think the smoke created by the juices hitting the charcoal is an important component.
I'm not suggesting you should use this technique or any other, but I can say that I've fed large groups using this method without any complaints other than "is there any more?"