sentences:  Three funnels were adopted because in earlier vessels, the two-funnel arrangement tended to obstruct views from the bridge, and by splitting the smoke into three funnels instead of two, the funnels could be thinner and thus less obtrusive.At some point after 1915, oil-firing capability was added to supplement the coal-fired boilers.The two outer propellers were three-bladed, and in diameter, while the center screw was four-bladed and in diameter.