Bar-bar-jiid (baaritaan jiidid) Dadku waxay doortaan gooseneck ama bar-ku-jiid si ay ugu xidhmaan trailer-ka qaabaysan ee haydarooliga iyadoo loo eegayo baahida gaadiidka dhabta ah. Xaaladdan soo socota ayaa ah in la isticmaalo baarka barbaradka: Markaad u leexanayso waddo cidhiidhi ah, waxaad u baahan tahay inaad gacanta ku hagto trailer dhan, way sahlan tahay in la isticmaalo bar-ku-jiida halkii aad ka isticmaali lahayd qoor goose. Gooseneck laguma shaqayn karo 4 ama 3 faylal isjiidjiid ah (marka modules trailer-ka ay isku xidhmaan dhinacba), bar sawir kaliya ayaa tagi kara. Marka trailer-ka uu ka yar yahay 7 sadar, waxaa fiican in la isticmaalo bar-bar-jiid, sababtoo ah trailer-gaaban ma samayn karo cadaadis ku filan oo biyo ah si gooseneck. Isteerinka gacanta, baarka sawirku wuu ka fudud yahay gooseneck.