§ 54. Construction against fire. All public vessels shall be so constructed that inflammable material about any machinery or apparatus involving danger of fire where such inflammable material is exposed to ignition, shall be shielded by some incombustible material so that the air may circulate freely between such material and the ignitable substances. Before granting a certificate of inspection, the inspector shall require that all necessary provisions be made throughout such vessel as he may judge expedient to guard against loss or damage by fire.