spandogs

from The Century Dictionary.

• A pair of iron bars linked together at one end and having sharp hooks at the other, used for grappling timber. See cut under dag.
• singular In the bending of barrel-staves, a bar of iron used as a holder to retain the curved shape of the staves until they have cooled, when they will not bend back.

from the GNU version of the Collaborative International Dictionary of English.

• noun plural A pair of grappling dogs for hoisting logs and timber.