Dragged into warp

[Billz]

Can a ship that doesn't have an active warp field, and that is being dragged in warp by a tractor beam, engage it's own warp drive while in an already active warp journey without suffering any damage?

[majormagna]

If I understand warp theory right, a ship being 'towed' at warp still needs a warp field around it.

 Let's say Ship A is being tractored by Ship B; Ship B will need to have extended it's own warp field to encompass both itself and Ship A for them to both safely travel at warp speeds.

 From what I gather, when Ship A re-engages it's own warp field, it must (somehow) keep it's field at the same frequency as Ship B's and, while the fields are still converged, remain at the same speed (relitively) as Ship B. The tricky bit would be cutting the tractor beam at the right point I think.

For example, in (an episode of) Enterprise, this happens, albeit without a tractor beam or grapplers, where the Columbia extends their field around Enterprise, while the Warp Core is shut-down and re-started.