Kammala jumla mai zuwa: Bayan barkewar Yakin Crimean, Chapman ya kasance tare da Rukunin 1st, wanda Yarima George, Duke na Cambridge ya ba da umarni, a matsayin babban jami'in injiniya. Ya shiga cikin
Yaƙin Alma kuma an ambaci shi a cikin sakonni na 28 Satumba 1854, yana ɗaukar umarnin ayyukan injiniya yayin kewaye da Sevastopol. Ya kasance a yakin Inkerman kuma an ambaci shi a cikin sakonni a ranar 11 ga Nuwamba, 1854, 23 ga Yuni, 1855 da 9 ga Satumba, 1855. A ranar 5 ga Yuli 1855 an sanya shi Abokin Abokin Bath kuma ya sami karramawa daga wasu gwamnatocin kasashen waje, gami da sanya shi jami'in aji na uku na Order of the Medjidie. Gwamnatin Burtaniya ta ba shi fansho don fitaccen sabis a ranar 23 ga Nuwamba 1858. A ranar 8 ga Afrilu 1856 an nada Chapman a matsayin Babban Injiniyan Masarauta a Gundumar London, kafin a canza shi zuwa Aldershot a watan Satumbar 1857. A ranar 1 ga Afrilu 1859 an ba shi mukamin Laftanar-Colonel. Daga 1 ga Satumba 1860 ya yi aiki a matsayin mataimakin mataimakin janar na Royal Engineers a Horse Guards na tsawon shekaru biyar. An sanya shi Knight Commander na Order of Bath a ranar 13 ga Maris 1867 kuma a ranar 8 ga Afrilu aka nada shi gwamna kuma babban kwamandan Bermuda. A ranar 1 ga Yuli 1870 ya yi murabus daga wannan mukamin kuma ya karɓi nadin Babban Sufeto na Fortifications da Daraktan Ayyuka a Ofishin Yakin.