2-1. Command Relationships.
Command relationships prescribe the chain of
command and the authority a commander has over an engineer unit.
a. Organic. Organic units are a permanent part of a larger unit. The
parent unit exercises full C2 over them.
battalions and separate brigade engineer companies are organic to
the parent unit.
b. Assigned. Assigned units are under the C2 of a higher headquarters
(usually above division level) on a relatively permanent basis.
Engineer units of an ENCOM are assigned to the theater army.
Attached units are under the C2 of a gaining commander
unless limitations are imposed by the attachment order.
commander's authority and responsibility is the same as that for
organic and assigned units, except personnel transfer and promotion
remain under the units parent organization. The gaining commander
OPCON units are under the gaining commander's C2, and the
parent unit retains responsibility for administrative and logistical
The gaining commander can use the engineer unit as he
would attached engineers without the burden of making logistical
arrangement. Within the North Atlantic Treaty Organization (NATO),
an allied formation commander does not have the authority to assign
separate employment of OPCON engineer unit components from another
An engineer unit that is OPCON to an allied
formation cannot be task-organized by the formation commander.
e. Operational command (OPCOM).
OPCOM units are under the United
States (US) unified or specified commanders C2, and the parent unit
In NATO, OPCOM gives a commander the authority to assign missions or
tasks, deploy units, reassign forces, and retain or delegate
operational and tactical control.
2-2. Support Relationships.
Support relationships show the manner of
support a commander receives. Command, administrative, and logistical
responsibilities remain with the parent engineer unit.
a. DS. Engineers in a DS relationship provide dedicated support to a
The supported commander assigns tasks directly to
the engineer unit and these tasks have priority over those from its
Command, administrative and logistical
responsibilities remain with the parent engineer unit which employs
engineer subunits to efficiently accomplish mission tasks.
relationship preludes further task organization of the engineer unit
by the supported maneuver commander.
b. GS. Engineers in a GS relationship provide support to the force on
an area basis instead of providing support a specific unit. Units
request support through the area commander on a task-by-task basis.
The commander then establishes priorities and assigns the task to an