Words to Describe bridgeheads

How bridgeheads often is described ("________ bridgeheads")

• shallow
• secure
• bank
• principal
• smaller
• organic
• continental
• colonial
• solid
• austrian
• necessary
• substantial
• irrawaddy
• egyptian
• several
• firm
• rhine
• vital
• more
• somme
• strong
• small
• income
• permanent
• seine
• japanese
• important
• soviet
• excellent
• few
• main
• sizable
• british
• northern
• dutch
• initial
• normandy
• american
• coastal
• further
• german
• narew
• established
• tiny
• precarious
• key
• russian
• european
• separate
• strategic
• valuable
• convenient
• narrow
• held
• numerous
• french
• major
• local
• multiple
• isolated