Stability Monitor

[nettersheim]

Good morning Guillermo,

Yes, we do.
In fact the use of GM-Meter for inclining tests is a "sub product" of the equipment.

In the case of inclining tests, it is used "only" to carry out the heel angle measurements. We use as a second mean of measurement (as stipulated by Solas and Intact Stability Code 2008, two means of measurement) a good and simple pendulum. The comparison between both measuring equipment are always very positive. But obviously the use of GM-Meter (which in that case is named GM-Test...) is far more easy. French administration and Class accept the use of the equipment provided it is doubled with one pendulum.

It is particularly useful for small ships/boats according to what I know (I have no experience of small ships/boats, only Solas or naval vessels).

The equipment is performing in parallel signal analysis (FFT) on the roll movement and extract the roll spectrum, with roll period peak, etc... especially when we slack the ropes for the inclining itself ; then the high precision of the sensor together with the dedicated signal treatment is able to lead to roll period, even if it is not the purpose of the measurement (basically only heel angle measurement for the inclining test). You are then able to measure radius of gyration (k) because inclining test gives you the position of the C. of G. together with displacement, etc...

Obviously it is far more expensive than a bloody piece of string, small weight and a trough to make a pendulum...

But the "profit" is may be elsewhere: only one pendulum means only one person reading the deflections, in the meanwhile an other person is conductiong the test globally while the equipment is recording the measurements automatically; you see if something is going wrong (non identified free surface for exemple is "seen" immediately by the GM-Test), etc... We carry out large vessel inclining tests (and draught survey) with 2 people only, ship in service, just few hours interrupting commercial operations in terminals. The difficult part of inclining test, as you know, being the ballast, tank, capacities and extra weight survey is done before or after and is not related to measurement itself and therefore means of measurement.

Hope this feedback is of some use.

François-Xavier Nettersheim

[Guillermo]

Thanks a lot, François Xavier.
Cheers.

[DCockey]

Is the "GM-Meter" the same equipment which Hook Marine sells (see first post), or similar equipment by a different maker?