Type 23 Distribution And Propulsion

Question 1

How many diesel engines are fitted to a type 23?

Answer 1

4

Question 2

What is the output of the generators?

Answer 2

600V
3 phase
61.2Hz
1.3MW

Question 3

Why does a type 23 use 600V rather than 450V?

Answer 3

450V doesn’t allow for a large enough range of speeds

Question 4

What breakers are fitted to a type 23?

Answer 4

Generator supply breakers
Motor generator supply breakers
Motor generator feeder breakers
Interconnector breakers
Ship/shore supply breakers
Electric motor breaker
Diesel generator alternative supply breakers

Question 5

What does a converter regulator do?

Answer 5

Converts the 600V into 750V DC to feed the propulsion motor

Question 6

What voltage is required for ships services? How is it produced?

Answer 6

450V and 115V

It comes from a motor generator set supplied by the 600V system to produce 450V which is returned to the 450V bus bar

Question 7

What are EDPs and how many types are fitted?

Answer 7

Electrical distribution panel

3 types

Question 8

What are shedable service?

Why do we need them?

Answer 8

A shedable service is a service that you may do without.
We need them so that if a supply generator is cut off then we can shut down systems so that the important stuff can still fully function

Question 9

What would happen if you lost both motor generator sets?

How is this achieved?

Answer 9

You would reset the diesel generators to generate 450V.

You would do this by opening the supply breakers and then close the diesel generator alternative supply breaker after turning the converted generator switch to 450V test then 450V

Question 10

What services does the emergency switchboard supply?

Answer 10

Steering motors
HPSW systems
Surgery
Smoke clearance exhaust fans
Portable pump sockets

Question 11

Why is electric propulsion preffered in respects of submarines?

Answer 11

It’s quieter and that means that you can reduce the distance where you can be detected by a submarine and if you are too loud then you cannot hear the submarines when searching for them

Question 12

What is the EMACB?

Answer 12

Electric Motor Air Circuit Breaker

Question 13

What SRPM and speed in knots do 2 diesel generators produce?

Answer 13

65 SRPM

8 to 9 knots

Question 14

What SRPM and speed in knots does 3 diesel generators produce?

Answer 14

80 SRPM

10 to 12 knots

Question 15

What SRPM and speed in knots does 4 diesel generators produce?

Answer 15

90 SRPM

14 knots

Question 16

In the event of damage to the SCC, how can the propulsion motors be controlled?

Answer 16

They can be controlled locally at the converter

Question 17

Describe the cooling system for the propulsion motors?

Answer 17

Cold air from the outside is drawn in by fans
The air is then forced across the poles armature commutator and brush gear before exiting the motor on the commutator side. The warm air is then passed over a sea water cooled heat exchanger before being pushed into the engine room.

Question 18

Describe the normal cooling for the converter cubical?

Answer 18

The converter cubical has a recirculating system of air that passes over a sea water heat exchanger to remove heat and is pushed around by fans.

Question 19

Describe the emergency cooling for the converter cubical?

Answer 19

In an emergency there are 2 panels which can be removed and the air can be brought in from outside the cubical to cool the converter