Instead of putting all alter table operations into a single command, provide an option to have them split into multiple individual operations.

Instead of this:
ALTER TABLE JobTime ADD
UUIDPayWeek nvarchar (50) NULL,
XMLEquipment xml NULL,
XMLConsumables xml NULL;
GO

Do this:
ALTER TABLE JobTime
ADD UUIDPayWeek nvarchar (50) NULL
GO

ALTER TABLE JobTime
ADD XMLEquipment xml NULL
GO

ALTER TABLE JobTime
ADD XMLConsumables xml NULL
GO