Figure 4-1 diagrams the main power system single line on page 4-7.
Figure 4-2 diagrams the main power system control cable block diagram on page 4-8.
Figure 4-3 diagrams the main power system circuit switcher on page 4-9.
Figure 4-4 diagrams the main power system switchgear load breaker on page 4-10.
Figure 4-5 diagrams the main power system switchgear incoming breaker on page 4-11.
:
b. Breakers.
The switchgear line-up contains two incoming, one tie, and eight load breakers. Each breaker has a relay/control compartment containing a control switch, indicating lights, relays, control wiring, and terminal blocks. The breakers have electrical and mechanical interlocks to prevent inadvertent operation, open/close springs, spring charging motors, position switches, and close and test positions.
http://armypubs.army.mil/eng/DR_pubs/dr_a/pdf/tm5_694.pdf

From the diagrams (esp. 4-1) I learned that the “load breaker” is

Differentiation of mainly used switches in substations:

Area Switchgear, controlgear and fuses / Switching devices
IEV ref 441-14-05
en disconnector
a mechanical switching device which provides, in the open position, an isolating distance in accordance with specified requirements

Note – A disconnector is capable of opening and closing a circuit when either negligible current is broken or made, or when no significant change in the voltage across the terminals of each of the poles of the disconnector occurs. It is also capable of carrying currents under normal circuit conditions and carrying for a specified time currents under abnormal conditions such as those of short circuit.
http://www.electropedia.org/iev/iev.nsf/display?openform&iev...

Area Switchgear, controlgear and fuses / Switching devices
IEV ref 441-14-10
en (mechanical) switch
a mechanical switching device capable of making, carrying and breaking currents under normal circuit conditions which may include specified operating overload conditions and also carrying for a specified time currents under specified abnormal circuit conditions such as those of short circuit
Note – A switch may be capable of making but not breaking short-circuit currents.
de Lastschalter Area Switchgear, controlgear and fuses / Switching devices

IEV ref 441-14-11
en earthing switch
a mechanical switching device for earthing parts of a circuit, capable of withstanding for a specified time currents under abnormal conditions such as those of short circuit, but not required to carry current under normal conditions of the circuit
Note – An earthing switch may have a short-circuit making capacity.
http://www.electropedia.org/iev/iev.nsf/display?openform&iev...

http://www.electropedia.org/iev/iev.nsf/display?openform&iev...
Area Switchgear, controlgear and fuses / Switching devices
IEV ref 441-14-12
En switch-disconnector
a switch which, in the open position, satisfies the isolating requirements specified for a disconnector
de Lasttrennschalter

Area Switchgear, controlgear and fuses / Switching devices
IEV ref 441-14-20
en circuit-breaker
a mechanical switching device, capable of making, carrying and breaking currents under normal circuit conditions and also making, carrying for a specified time and breaking currents under specified abnormal circuit conditions such as those of short circuit
de Leistungsschalter
http://www.electropedia.org/iev/iev.nsf/display?openform&iev...

Inductive load switch translated from German
DE 202011001893 U1
Abstract translated from German
Inductive circuit breaker which is characterized in
http://www.google.com/patents/DE202011001893U1?cl=en
Induktiver Lastschalter
DE 202011001893 U1
Abstract
Induktiver Lastschalter der dadurch gekennzeichnet ist,
http://www.google.com/patents/DE202011001893U1?cl=de

Load break switches for medium voltage with a vacuum interrupter translated from German
DE 4242379 A1
http://www.google.com/patents/DE4242379A1?cl=en
Lasttrennschalter für Mittelspannung mit einer Vakuumschaltröhre
DE 4242379 A1
http://www.google.com/patents/DE4242379A1?cl=de
(Hersteller Siemens)

Housing +E0 (load circuit breaker) may only be opened when all other housings are fully closed.
bonfiglioli.com
Das Gehäuse +E0 (Lasttrennschalter) darf ausschließlich geöffnet sein, wenn alle anderen Gehäuse vollständig geschlossen sind.

bonfiglioli.com
Switch off load circuit breaker.
bonfiglioli.com
Lasttrennschalter ausschalten.
http://www.linguee.de/deutsch-englisch/search?source=auto&qu...
(Anm.: Italienischer Hersteller)

Lasttrennschalter – Erdungsschalter
Load-break switches – Earthing switches
http://www.ormazabal.com/sites/default/files/ormazabal/produ...
(Anm.: Spanischer Hersteller)