An aerial device for operating on energized powerlines is disclosed. The aerial device may have a boom assembly with a lower, electrically non-insulating boom section coupled to an upper, electrically insulating boom section. The lower and upper boom sections may be coupled by a pinned connection that utilizes structural collars and structural pins to handle loads applied to the upper boom section. The upper boom section may articulate relative to the lower boom section using a 4-bar mechanism employing a split pivot pin that enables a greater range of motion for the articulation. A modular sled that can be coupled to various boom assemblies is also disclosed.