Pedzisa mutsara unotevera: Dumbarton Rail Bridge (yainzi Dumbarton Point Bridge kana kuti, Dumbarton Bridge; chimwe chezvinhu zvikuru zveDumbarton Cut-off rail line) yakatsigirwa naE. H. Harriman. Pamberi pokupedzwa kweDumbarton Cut-off, kutakura zvinhu kwechitima kwakapfuudzwa kuOakland ndokuendeswa kuSan Francisco. Basa rokutanga rakatanga muna 1904 nokurambwa kwenyika paDumbarton Point, uye kubatanidzwa kweCentral California Railway Company, yakasikwa nevakuru vakuru veSouthern Pacific nechinangwa choga chokuvaka njanji kubva kuNewark kuenda kuSan Mateo. Paiva nokushorwa kwebhiriji nemapoka emabhizimisi omunharaunda, uye United States Army Corps of Engineers yakaita hurukuro yavose muna August 1906 ichikoka vanhu kuti vataure nezvezvirongwa zvebhiriji racho. Henry Rengstorff akataura kuti zambuko raizotadzisa kufamba kwemvura, uko kwaidiwa senzira yokuchinjira kana pakaitika kurova kwezvitima kana njodzi dzinongoitika dzoga, dzakadai se
kudengenyeka kwenyika kuchangobva kuitika.