Dear Fabio Franceschetti,,
A few months ago I went to the Redipuglia Military Memorial Museum where I had the opportunity to see a hard hat diver's pump on display, of which I enclose a photo I took in the circumstance.
There were no data or information and the person in charge of the Museum, whom I asked, mentioned me generically about the presumed origin from La Spezia city.
I remember I read that, at the end of the First World War, a hard hat diving company from La Spezia worked underwater in the port of Trieste.
I thought that perhaps (in the case the pump was not already in use at the “Regia Marina” [Royal Italian Navy]), there might be a relationship with the hard hat diving company that worked in Trieste city at the time.
Could this be a possible hypothesis? May I have some information about the hard hat diving pump of the Museum?
Thank you for your kind attention
Stefano Berutti

Question asked by Stefano Berutti on 30/03/2020

Pictures attached to the application

The question you ask me, for which I thank you, is very interesting. Although it is not easy to analyze a hard hat diver's equipment through a single photo, without looking closely at the details that often prove to be very useful for the investigation, I will try to answer to the various issues related to your question.
It has to be considered as a preliminary remark that such equipment was a working tool, as such subject to wear and tear and frequent repairs, and as a result, those found today, even in the collecting market, often have parts from different manufacturers or are incomplete, as in the present case.
The hard hat diving pump of the Redipuglia Museum has some distinctive elements that lead me to think that it is the mechanism of a S.I.A.S. hard hat diving pump, where are missing the original wooden case and other pieces. Originally it must have been similar to the one shown in the following picture (please see picture #1).

fig. 1


In the latter there are two original plates with the name of the producer, the first one positioned outside the case between the two pressure gauges and the second one positioned inside the wooden cover, having the inscription: "MATERIALI FOR PALOMBARI [ITEMS FOR HARD HAT DIVERS] - S.I.A.S. - LA SPEZIA - SALVATAGGI E RICUPERI SUBACQUEI [RESCUE AND UNDERWATER RECOVERY]" (please see pictures #2 and #3).

fig. 2


fig. 3


On the "S.I.A.S." company, unfortunately, we do not have much information (and by the way I invite those who have documents or materials to contact me on the website).
We are not sure when the Company will be established. Certainly it is active after 1930, because in that year the Ligurian city took the name "La Spezia" indicated on the plate. In the book Angelo Belloni. Cinquant’anni di mare [Fifty years at sea]. Memorie 1900-1950 [Memoirs 1900-1950] by Achille Rastelli, Milano Mursia 2008, pp. 177-178, reads: "Alle mie [di Belloni] continue proteste perché la marina si serviva di una ditta inglese, si rispose facendo trasformare la SIAS di La Spezia (Zannoni) che stava per Società Italiana Apparecchi Siebe Gorman, in SIAS, Società Italiana Apparecchi di Salvataggio, nella quale entrava, al posto della Siebe Gorman, la Pirelli, concessionaria della Siebe Gorman. Zannoni si impegnava a fabbricare il residuo dei 4.000 Davis [respiratori subacquei per la fuoriuscita dai sommergibili sommersi] in Italia, a Milano, anziché farli venire da Londra, ma i diritti percentuali partivano, egualmente per l’Inghilterra, nel 1935, quando la guerra d’Africa ci metteva più o meno contro gli inglesi.”
[To my (Belloni's) continuous protests because the [italian] navy was buying hard hat diving items from an English company, the response was that SIAS company in La Spezia (Zannoni), which meant Società Italiana Apparecchi Siebe Gorman [ Italian company of Siebe Gorman devices ], was transformed into SIAS, Società Italiana Apparecchi di Salvataggio [ Italian company of rescue devices ], in which, instead of Siebe Gorman, Pirelli [ the Pirelli company  from Milan, Italy], the Siebe Gorman dealer, entered in the company. Zannoni committed to manufacturing the remaining of the 4,000 Davis [underwater respirators for the escape from submerged submarines] in Italy, in Milan, instead of having them come from London, but the percentage rights sent, equally to England, in 1935, when the African war put us more or less against the English people"].

Italo Zannoni had long been the agent for Italy, and for the Italian colonies, of the English hard hat diving equipment Siebe Gorman.
Thus no wonder when in the older S.I.A.S. hard hat diving pumps the pressure gauges are marked "Siebe Gorman" (please see picture listed below). We will call these pumps "first type" (please see picture #4).
During the autarchic period, following the sanctions deliberated in the years 1935 and 1936 by the League of Nations for the Italian invasion of Ethiopia, the "second type" S.I.A.S. hard hat diving pumps began to appear, with gauges marked "S.I.A.S. - La Spezia" and no longer "Siebe Gorman" (please see picture #5).

fig. 4


fig. 5



fig. 6


Please find below three pages of the catalog MATERIALE PER PALOMBARI E PER LAVORI SUBACQUEI. SOCIETA’ ITALIANA APPARECCHI DI SALVATAGGIO “S.I.A.S.”. ANONIMA CON SEDE IN MILANO. LA SPEZIA. Casella postale 144 [ Items for hard hat divers and underwater works. Italian company of rescue devices. Joint-stock company with headquarters in Milan. La Spezia, P.O. Box #144 ], unfortunately undated and without editorial information, concerning the two-cylinder S.I.A.S. hard hat diver pumps (please see pictures #6 - #7 - #8).

fig. 7


fig. 8


fig. 9


fig. 10


In the catalog there are the S.I.A.S. hard hat diving pumps of "first type", where many details refer to the English company Siebe Gorman ones: not only the illustrated gauges show the pressure indicator with the classic Siebe Gorman "dovetail" shape, but you can clearly notice the "twisted" element, Siebe Gorman style, of the crankshaft. It is this detail which, as illustrated in the photos below, leads us to conclude that the hard hat diver's pump of the Military Sacrarium Museum of Redipuglia is a S.I.A.S. "second type" hard hat diver's pump (please see pictures #9 - #10).
Another important difference between the S.I.A.S. hard hat diving pumps of "first type" and the S.I.A.S. hard hat diving pumps of "second type" is found in the serial numbers.
The hard hat divers pumps of "first type" have Siebe Gorman serial numbers like the ones shown in the pictures listed below (in this case the serial number is "6360", please see pictures #11 - #12).

fig. 11


fig. 12


The "second type" hard hat diving pumps, instead, have different S.I.A.S. serial numbers, as in the following pictures (in this case the serial number is "SIAS 112", please see pictures #13 - #14).

fig. 13


The serial numbers of the Museum pump, as can be seen in the detail of the photo sent to us (please see below), reinforces the conclusion that it is a "second type" S.I.A.S. hard hat diving pump (please see picture #15).
The Museum pump is missing the S.I.A.S. writing under the serial number, which has a high serial number, "257", compared to the previous hard hat diving pump with the serial number "SIAS 112".

Another feature of the hard hat diving pump, for sure an original hard hat diving pump, leads us to believe that it probably comes from the S.I.A.S. company, even though it does not have the corresponding S.I.A.S. markings. The unmistakable element is the shape of the overflow drain channel of the pistons cooling tank (functioning equal to the upper drain that does not allow the water of the sink, once full, to spread on the ground with the tap still open, but to be conveyed into the overflow drain channel), present on S.I.A.S. diver pumps. It has been highlighted in the following two photos (please see pictures #16-17).

fig. 14


fig. 15


fig. 16


fig. 17


The same type of overflow drain channel can also be seen in the Museum pump, as shown in picture 18.

fig. 18


For the sake of completeness, a detailed photo of the overflow drain channel is shown in the Italian pumps SALVAS (Società Anonima Lavorazioni Varie e Apparecchi di Salvataggio [joint-stock company of various works and rescue equipment ]) (please see picture #20). And a Siebe Gorman hard hat diving pump (please see picture #19).

fig. 19


fig. 20


Finally, some considerations on the "hard hat diving company from La Spezia ".
I believe that the company of civil underwater works hailing from La Spezia city to which we must refer, for its importance, is the "Società Anonima Fratelli Serra" [Serra brothers joint-stock company] owned by the hard hat divers Fortunato, Giacomo and Antonio, sons of Giovanni, a hard hat diver of Sardinian origin.
Ulderico Tegani, on page 132 of the book Viaggi nel Mondo sommerso (Avventure di palombari) [ Travels in the underwater world (Hard hat divers adventures) ] published by A. Mondadori Publisher in the year 1931, writes that “non si può parlare di palombari Italiani senza parlare dei fratelli Serra” [people cannot speak of hard hat Italian divers without speaking of the Serra brothers] and “non si può parlare di palombari Italiani senza parlare dei fratelli Serra”, “in questo nome, volere o no, si riassumeva e si riassume ancora, per i più, tutta la classe dei lavoratori subacquei, con tutto il significato che le compete d’una accolta di valorosi. Era, insomma, ed è, un nome rappresentativo, un nome prestigioso, in cui si compendia e s’identifica tutto un periodo di attività palombaristica, che da esso riceve luce e splendore.” [in this name, will or not, the whole class of hard hat divers was and still is summarized, for most people, with all the meaning that belongs to it of a group of brave hard hat divers. Therefore it was and it is, a representative name, a prestigious name, in which a whole period of hard hat divers' activity, which receives light and splendour from it, is summarized and identified].
Francesco Fortunato Serra was born in Genoa in 1846. When he had not yet reached the age of twenty, he had to take over the leadership of the family and business because of the sudden death of his father, which occurred during the recovery work of a tartane shipwrecked at a depth of more than 30 meters in the Gulf of La Spezia.

King Umberto appointed the Serra brothers as Knights of the Crown of Italy after their contribution to the rescue - carried out with the "Impresa Genovese di Salvataggi Marittimi" [Genoese company of underwater  salvages] - of the English battleship Sultan, which had run aground among the rocks on March 15, 1888, at 12 miles from Malta and two hundred meters from the island of Comino, causing serious damage (rescue that later, on the "Secolo XIX" newspaper of September 9, 1911, someone wanted to attribute to the company Fratelli Baghino e Figli [Baghino brothers and sons] in addition to the "Impresa Genovese di Salvataggi Marittimi").
After the death of Fortunato and Giacomo, Antonio continued to keep the family name alive, successfully completing several memorable feats, including the rescue of the ocean liner Sirio, shipwrecked in the year 1905, and the double refloat of the cruiser San Giorgio in the year 1911.
The company "Fratelli Serra" took care of the underwater demolition of the German battleship Viribus Unitis, which sank in 1918 at a depth of 39 meters in the waters of Pula by the major of the naval engineer department Raffaele Rossetti and medical lieutenant Raffaele Paolucci, with the help of the Palombari Smobilitati [demobilized hard hat divers] in the year 1922.
Antonio Serra died in Livorno city in the year 1929.
Please find below is a photo (please see picture #21) of the original stamp of the company "F.lli Serra" [Serra brothers].

fig. 21


Thus, on the basis of the historical elements known so far about Serra brothers' company of  Spezia, briefly mentioned above, it does not seem that the hard hat diver's pump of the Redipuglia Museum, which can be dated after 1935, can be referred to that company, since the historical periods do not coincide.
The condition of the pump makes me think more of it being used by a private hard hat diver, rather than by a structured underwater hard hat diving company, the Italian Royal Navy or later the Italian Navy

answer given by Fabio Franceschetti on 30/03/20A20

Surname and name
Berutti Stefano
Area of ​​interest