Warning Bell in the Crow's Nest

[Arun Vajpey]

(The only other thread about this was closed and so I had no option but open a new one to ask the question)

Are there any details about the make and model of the bell in the Titanic's crow's nest, the one that lookout Fleet rang 3 times when he saw something in the horizon? The related information that I am interested in is whether there were any specifications about its sound level when rung firmly? As it was designated as a warning bell, I imagine it was on the loud side.

As the ship was moving forward when Fleet rang the bell that Sunday night, the wind would have carried the sound aft, I assume. So, approximately how far aft would he sound been heard relative to a awake and on duty crew member with normal hearing?

 

[Samuel Halpern]

As you know Arun, QM Olliver said he heard it while amidships on the standard compass platform. Yet, QM Rowe on the poop deck aft said nothing happened until he felt the ship strike something, implying that he didn't hear anything beforehand. The lookout bell was also heard by those coming out on deck from the forecastle. I don't know of any requirements regarding sound level.

 

[Steven Christian]

(The only other thread about this was closed and so I had no option but open a new one to ask the question)

Are there any details about the make and model of the bell in the Titanic's crow's nest, the one that lookout Fleet rang 3 times when he saw something in the horizon? The related information that I am interested in is whether there were any specifications about its sound level when rung firmly? As it was designated as a warning bell, I imagine it was on the loud side.

As the ship was moving forward when Fleet rang the bell that Sunday night, the wind would have carried the sound aft, I assume. So, approximately how far aft would he sound been heard relative to a awake and on duty crew member with normal hearing?

According to E.T.'s article on the bridge the bell was 15". It's job was to alert to the bridge. The crows nest was relatively close to the bridge so probably didn't a sound volume level of 11. (Sorry couldn't resist). Titanic had other bells that they used for other functions. Even electric one's on the water tight doors so the crows nest bell was mainly to alert the bridge and then call on the phone. Couldn't find any specs on decibel levels. Cheers.

On Titanic's Bridge

Who did what on Titanic's Bridge?

www.encyclopedia-titanica.org

Titanic Lookouts and Crow's Nest | Titanic Pages - Titanic History Website

 

[Arun Vajpey]

As you know Arun, QM Olliver said he heard it while amidships on the standard compass platform

Thanks Sam. That's what I have been trying to get at since doubts were expressed from certain well recognized quarters about QM Olliver's veracity. It was even suggested that Olliver had sneaked off somewhere below decks to have a quick smoke - if you recall. Perhaps the accuser had access to evidence that no one else did.

I believe that QM Olliver was where said he was and doing what he said he was doing on the Standard Compass Platform.

According to E.T.'s article on the bridge the bell was 15". It's job was to alert to the bridge. The crows nest was relatively close to the bridge so probably didn't a sound volume level of 11

Agreed, but on that still, quiet night with the Titanic moving forward at about 22 knots, the sound of the 3 bells could easily have carried to the Compass Platform, which was around 250 feet aft of the bridge?

 

[Arun Vajpey]

QM Olliver said he heard it while amidships on the standard compass platform. Yet, QM Rowe on the poop deck aft said nothing happened until he felt the ship strike something, implying that he didn't hear anything beforehand

Thanks to information provided by Thomas Krom on another thread, I calculated that when it reached Rowe's position, the intensity of the sound of those 3 bells from the Crow's Nest would have been around 1/10 of what it was when it reached Olliver's position. No wonder that Rowe could not hear it.

 

[Steven Christian]

Thanks Sam. That's what I have been trying to get at since doubts were expressed from certain well recognized quarters about QM Olliver's veracity. It was even suggested that Olliver had sneaked off somewhere below decks to have a quick smoke - if you recall. Perhaps the accuser had access to evidence that no one else did.

I believe that QM Olliver was where said he was and doing what he said he was doing on the Standard Compass Platform.

Agreed, but on that still, quiet night with the Titanic moving forward at about 22 knots, the sound of the 3 bells could easily have carried to the Compass Platform, which was around 250 feet aft of the bridge?

It sounds reasonable to me and the Quarter Master said he heard it on the platform. That's less than a football field away. But under different conditions I don't know. It's like where I live. Some nights you can't hear any of the trains. Other nights it sounds like they are next door. Not sure why but would guess it might have to do with changing air density/temperature. Cheers.

 

[Samuel Halpern]

Not sure why but would guess it might have to do with changing air density/temperature. Cheers.

And the direction of the wind.

 

[Steven Christian]

And the direction of the wind.

Yes that would make sense. On the night of Titanic being exceptionally calm minus the relative wind from the ships movement probably wasn't much of a factor in affecting the sound. But I wonder if crewmen who would here bells going off all the time didn't just learn to tune them out after awhile.

 

[Arun Vajpey]

On the night of Titanic being exceptionally calm minus the relative wind from the ships movement probably wasn't much of a factor in affecting the sound

True, but completely irrespective of the wind, sound follows the Law of Inverse Squares. Thus, QM Olliver on the Compass Platform was approximately 275 feet from the source of the 3 bells whereas QM Rowe on the "Afterbridge" was about 640 feet away ie more than twice Olliver's distance. Therefore, when the sound of those 3 bells reached Rowe's position, it would have dissipated to less than a tenth of its intensity of what it had been to Olliver.

 

[Samuel Halpern]

But subjective hearing levels are not linear. Something 1/4 as loud by measured intensity doesn't sound that low. That's why sound levels are usually expressed in dB values.

 

[Jim Currie]

When a ship is underway, she does not move silently through the water. in fact, the quieter the weather - the more apparent the noise she creates becomes.

Those of you who have sailed in yachts and on ships will know that wind does not contribute to noise below 20 knots, However, above that speed, it whistles through every nook and cranny and vibrates mast and funnel stays.

In addition, the bow wave of a fast ship in a seaway, is inaudible. However, in flat calm, it swishes out on either bow and creates noisy little 'slapping rollers'.

On that night, Titanic was making 22.5 knots by patent log, so she had a head wind of 22.5 knots acting on her masts stays, halyards, and funnel No.1
In addition, there would have been the steady 74 per minute thump-thump of the engines - normally drowned out during the day, and the noise of six huge electric ventilator fans drawing hot, humid air from no less than five boiler rooms. To cap it all there would have been activity noises rising through the fidleys in front of each funnel.
Incidentally, if you look at the profile plans on this site, you will see that the Standard compass platform was bracketed between two boiler room ventilation fans.