An Overview of Underwater Connectors

Round 1

Reviewer 1 Report

The article presents an overview of underwater connectors. The article presents the characteristics of underwater connectors, their history and construction.

According to me, the article lacked a description related to the evaluation of connectors reliability. It is known that there have been connectors failures, it is worth mentioning this in the article.

Author Response

See the attachment. 

Author Response File: Author Response.docx

Reviewer 2 Report

This paper provides an overview of underwater connector technology.  It is one of two papers of its kind and adds significantly to prior work in reference [20] by providing overviews of key underlying principles behind how electrical and optical contacts work.

The authors' proposal of functional units is a good one and serves to structure exposition well.  The authors provide some useful quantitative summary tables for a few manufacturers' offerings.

The authors provide an overview of technical literature devoted to general (terrestrial) connector technology.  Some connections are made to the underwater realm, but a more thorough exposition would be welcome.  The authors point out that much of the detail on how underwater connectors actually work is subject to trade secrets and therefore not easily attained.  Pointing out specific gaps in community knowledge would be preferable over a blanket statement.  

In general I would have preferred an increased focus on the low end connectors series like the Subconn Circular.  These are orders of magnitude less expensive than the hot-stab type connectors featured in, e.g., TE's offerings.  I suspect the engineering principles are more subtle in the low-end offerings.  The sealing unit is, I suspect, particularly subtle, but I may be mistaken.  There are certainly many more rubber-molded connectors in use than hot-stabs, and outside of industry, the use of anything but rubber-molded connectors is not common. 

The attached annotated manuscript has more directed comments as well as a few important typographic changes that I think better capture intent.

Comments for author File: Comments.pdf

Author Response

see the attachment. 

Author Response File: Author Response.docx

Reviewer 3 Report

First at all, thanks to the authors to have the idea of writing a review of "underwater connectors".

 

 

Line 10 and lines 49-50

“Due to patent protection, the key technologies of underwater connectors are mostly confidential …”

This is not really true; “patent protection” means that you cannot copy without authorization. The patents are public. Another question is that you have to pay a subscription to the patent office (like IEEE or Elsevier to Access to several papers) to access to all the documentation (depending on the country).

 

The main problem in underwater connectors is that it is an area mainly focused in to solve a specific problem for unique and specific application. This philosophy is the opposite of the classic COST, where the devices are made without a target application.

 

In general, the cost of to develop an underwater connector is very high. If you are in a low cost solution, your problem basically is to collect all particular solutions and take a decision about what of all available from multiple provides fits your target application.

 

 

Lines 25-26

 

When 70.8% of our planet’s surface is covered by oceans, it seems perplexing that the Earth is called “Earth” [1].

I am perplexed with this first sentence in the introduction ;) Without the joke, it is well known why the Earth is called Earth. The water only is a puddle over the Earth, despite of the water “cover” the 70%, this H2O element represent a pool of 13km deepest section in an Earth with a radius of 10500 km.

 

 

If you include a reference, you must provide some details about. For example, Line 37 makes reference to ELEVEN (11) references with a couple of sort sentences in a single line.

 

 

Line 79

 

Authors include the word “tribology” in underwater connectors. In general, this kind of connectors are designed to be always joined/connected. The term tribology is related to the “relative motion” of two surfaces. The tribology is mandatory in for example plug & play connectors like USB or jacks, however its usage in this kind of connectors is not clear.

 

Take care, Figure 1 is not a schematic diagram. It is basically a 3d CAD view of a connector. This image is taken from a reference. Please each image that it is taken from other source, add the reference in its caption.

 

All figures must be referenced with its own reference manual. Do not use the text of your paper to make the reference to a webpage. For example, this is the case of lines 207-209.

 

 

Lines 227, 233, 239, 244 and 248: It is not common see a definition table, dictionary that all descriptions begin with the same words “A functional unit that”. Just to simplify the writing you can do:

 

The definition of the functional units are as follows:

• Connecting Unit provides ….

 

 

As summary, this review uses 2 sections to describe the Connecting Unit. One for electrical and other to optical transmissions. Those Sections are described from page 7 line 254 up to page 13 line 450. That is close to 200 lines with multiple images and formulas.

 

The Sealing Unit and Pressure-Balance Unit are described from Page 13 to 14 in only 505-451= 45 lines and they use only a single image (Figure 14).

 

The section 6, Aligning and Locking Unit, is described in 23 lines (506-229) using 2 figures.

 

Finally, the authors discuss and conclude their review with a summary of their paper.

 

The key point here: what does a reader expect from a review paper entitled “underwater connectors”?

 

From my point of view, a reader wants to be clear informed about the problems and also how those problems have been solved in this area.

 

The paper sections about the connecting unit presents classical connector theory. This theory is not specific for underwater connector. It belongs to ordinary connectors. All presented theory is jet well known in this research area.

 

The big issues in underwater applications are the pressure and the conductivity of the water. However, the authors do not present clearly this problem. The reader of this paper can only find some information related to these real problems in Section 5 with 45 lines in total of 740 lines.

 

The authors must reduce their classical connector contents in “electric and optical” unit sections. And focus their review expanding the Section 5. That is, to explain how to solve the pressure and conductivity/isolation problems.

 

In addition, they must decouple the aligning and locking unit section. Nowadays, the aligning is not a problem because the optical connectors from non-underwater solutions still valid for underwater applications.

 

Other issue is the locking unit. In underwater application it can be considered a real nightmare. The main question about the locking is: “can it be done underwater by divers or a rover? or it requires to do the plug-in air?” Unfortunately, the pressure problem arises, and this issue must be addressed in this paper.

 

Author Response

see the attachment. 

Author Response File: Author Response.docx

Round 2

Reviewer 3 Report

Congratulations to the authors for their effort to update their paper. From my point of view, now it is ok. However, before to publish, please check and correct next minor mistakes:

 

Line 123 & 126 -> “Basically 3D CAD” -> “Basic 3D CAD view”

Adverb … Basically

Adjective … Basic

 

Writing style:

Line 194 - can protect -> protect

Line 252 - con-tact -> contact

Line 278 - can also increase -> increases

 

Usage of term: “Schematic diagram”. Please note that this term is used in “electronics” to describe a circuit. It implies the usage of components and connections/wires. In this sense, it’s usage in all Figures could mislead a reader. Please check these other alternatives:

 

Line 276 - Figure 8. Current flow distribution of two cables depending on their contact surfaces.”

Line 355 - Figure 10. Schematic view

 

 

Take care. In telecommunications, the dB usage requires a little expertise level. The sign of a dB value express if this magnitude is an attenuation or amplification. To avoid the double negation, when those values are expressed in a text, the writer must take too much care. For example, an amplification of -3dB means an attenuation of 3 dB (half power). In this sense, when you write an attenuation of -3 dB, you really are amplifying a 3 dB (double power). To avoid this "writing problem",  the attenuations are expressed without negative sign. Look to your reference 50. In this sense:

 

Line 365 - Insertion Lost Formula is positive (please check your 50 reference, page 189, equation 7.7).

 

LIns = 10 Log (Po/Pi)

 

Line 394 - Like previously, Lreturn is positive.

 

Equations 5 and 6 are contradictory (5 is wrong, please remove it) and rewrite line 397.

 

Author Response

See the attachment. 

Author Response File: Author Response.docx