English: Cover of the May 1947 publication of "Our Yard" magazine for the employees of Sun Shipyard in Chester, Pennsylvania (an "in-house" magazine published without copyright). Photo by Al Knott, a shipyard employee, shows the hammer-head crane. See page 15 for a description at http://sunshiporg.homestead.com/ouryard/oy_4705.pdf
Note that it may still be copyrighted in jurisdictions that do not apply the rule of the shorter term for US works (depending on the date of the author's death), such as Canada (50 p.m.a.), Mainland China (50 p.m.a., not Hong Kong or Macao), Germany (70 p.m.a.), Mexico (100 p.m.a.), Switzerland (70 p.m.a.), and other countries with individual treaties.