howitzers were mounted on Lorraine 37L tractors to create self-propelled guns, designated 15 cm sFH13/1 (Sf) auf Geschuetzwagen Lorraine Schlepper (f). See also 15 cm sFH 02 : German predecessor Weapons of comparable role, performance and era 6 inch 26 cwt howitzer - British equivalent Canon de 155 C modèle 1917 Schneider - French equivalent Obice da 149/12 - Italian version of the sFH13 produced under license In literature Siegfried Sassoon expressed the British respect for the "five-nine" in his World War I poem Counter-Attack Timothy Findley mentions "5.9s" in his book The Wars Wilfred Owen mentions being shelled by "Five-Nines" in his poem Dulce et Decorum est Robert Graves, in Good-Bye to All That, says "five-nines [were] called 'Jack Johnsons' because of their black smoke" in reference to "the boxer Jack (John Arthur) Johnson (1878-1946), the first black American world heavyweight champion (1908-1915)." Citations Sources Engelmann, Joachim and Scheibert, Horst. Deutsche Artillerie 1934-1945: Eine Dokumentation in Text, Skizzen und Bildern: Ausrüstung, Gliederung, Ausbildung, Führung, Einsatz. Limburg/Lahn, Germany: C. A. Starke, 1974 Gander, Terry and Chamberlain, Peter. Weapons of the Third Reich: An Encyclopedic Survey of All Small Arms, Artillery and Special Weapons of the German Land Forces 1939-1945. New York: Doubleday, 1979 Hogg, Ian V. German Artillery of World War Two. 2nd corrected edition. Mechanicsville, PA: Stackpole Books, 1997 Ralph Lovett, 15 cm. schwere Feld Haubitze 1913 Ralph Lovett, 15 cm. lang schwere Feldhaubitze 1913/02 Ralph Lovett, Development of German Heavy Artillery External links List and pictures of WW1 surviving 15 cm sFH 13 and 15 cm sFH 13 lang howitzers World War I howitzers World War I artillery of Germany Artillery of the Ottoman Empire Artillery of the Netherlands World War II field artillery World War II artillery of Germany 150 mm artillery