By the early 1900s, a standard design had evolved that lasted throughout the steam and early diesel eras: an 8,000-11,000 gallon metal tank perched on a metal flatcar-like underframe. The one big change during that time was the transition from riveted to welded construction, beginning in the late 1930s. Car builders introduced X-ray inspection of welds to ensure safety, as well as giant annealing ovens that could heat-treat assembled tanks to relieve joint stress.
Welded tanks were stronger, less susceptible to rust and corrosion, and less likely to rupture in the event of a wreck. Choice of Operating Knuckle or Hook & Loop Couplers. Unit Measures: 18" x 3/8" x 4" x 6". The item "MTH 70-73051, G Gauge RailKing One Gauge Unibody Tank Car Norfolk Southern" is in sale since Friday, February 24, 2017. This item is in the category "Toys & Hobbies\Model Railroads & Trains\G Scale\Freight Cars".The seller is "vztech" and is located in Taunton, Massachusetts. This item can be shipped worldwide.