How literal is this phrase?

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donkey boiler:

Definitions:

  1. (nautical) an extra boiler (as a ship's boiler that is used while the ship is in port)

Examples:

  1. . An old group of volunteers had rigged one up outside , heated by a donkey boiler . While showering , you look out over the stunning nature reserve . There is
  2. Campbell took advantage of a near miss , to stop the ship . From a donkey boiler he created clouds of steam amidships and sending away the Panic party * . Then
  3. ' sle towards amidships 12 huge boilers can be seen in the distance , many donkey boilers lay beyond even further while a service tunnel runs the great length of the ship

Note: Please select the answers below carefully based on the definition which occurs frequently in the examples

Step 3: score of 0-5 for how literal is the phrase "donkey boiler"
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