Question: Intimidator 305 and Thunder Dolphin are what type of roller coaster?
Related documents: [0]  [DOC] Thunder Dolphin (サンダードルフィン ) is a steel roller coaster at the Tokyo Dome City Attractions amusement park, which is part of Tokyo Dome City in Tokyo, Japan. The ride was designed and constructed by Intamin. At 80 m tall, Thunder Dolphin is currently the 8th tallest continuous circuit roller coaster in the world, behind Kingda Ka, Top Thrill Dragster, Fury 325, Steel Dragon 2000, Millennium Force, Leviathan, and Intimidator 305. Following an incident in which a 25 cm long bolt fell from the ride while in motion on 5 December 2010, injuring a 9-year-old visitor, operation of the ride was suspended until 1 August 2013, when the ride reopened. [END] 
[1]  [DOC] Intimidator 305 is a steel roller coaster located at Kings Dominion in Doswell, Virginia, United States. Manufactured by Intamin, Intimidator 305 opened to the public on April 2, 2010, as the park's fourteenth roller coaster. The roller coaster is located in the Safari Village section of the park near Anaconda on the former site of the Safari Monorail ride. Standing at 305 ft tall and reaching speeds of 90 mph , it is the second Giga Coaster to be built in North America – the first was Millennium Force at Cedar Point. The $25 million investment was the largest of any ride in the park's history. It is named and themed after NASCAR driver Dale Earnhardt, who was also known as the "Intimidator." [END] 
Answer: 
steel roller coaster
steel roller coaster