After conducting research, I was unable to find any information regarding a boat ramp named Shelby County located in Illinois with the provided latitude and longitude coordinates. It is possible that the location or the name of the boat ramp may be incorrect.

In general, boat ramps can vary in width depending on the size of the body of water they service and the amount of traffic they receive. Boat ramps are typically designed to accommodate a variety of watercraft, including small fishing boats, recreational boats, jet skis, and kayaks or canoes.

To determine the specific information about a boat ramp, it is recommended to contact the local government or parks and recreation department in the area where the ramp is located. They can provide accurate and up-to-date information regarding the type of boat ramp, its width, the body of water it services, and the types of watercraft permitted.