How many boilers and engines did the Indiana have, put the answers in comma separated ascending order

Context: Indiana was 351 feet 2 inches long overall and had a beam of 69 ft 3 in and a draft of 24 ft. She displaced 10,288 long tons as designed and up to 11,688 long tons at full load. The ship was powered by two-shaft triple-expansion steam engines rated at 9,000 indicated horsepower and four coal-fired fire-tube boilers, generating a top speed of 15 knots. She had a cruising radius of 5,640 nautical miles at a speed of 10 knots. As built, she was fitted with a heavy military mast, which was later supplemented by a stern cage mast in 1910–1911. She had a crew of 32 officers and 441 enlisted men, which increased to a total of 586–636 officers and enlisted.

Answer: Two-shaft triple-expansion steam engines, Four coal-fired fire-tube boilers