The sinkings of the RMS Titanic on April 15, 1912, and the RMS Lusitania on May 7, 1915, were the most notorious maritime disasters of the decade, and inspired some inventions of similar design for safeguarding mail and valuables on ships.
But only one such device had stamps created for it: Marine Insurance stamps for Netherlands and Netherlands East Indies, listed as Scott GY1-GY7 for both countries.
Dutch inventor Cornelis Van Blaaderen (1875-1933) applied for a United States patent Dec. 13, 1913, for a buoyant safe — “drijvende brandkast” in Dutch.
Van Blaaderen’s floating safe was a large steel cylinder affixed to the deck of the ship with clamps that would release if the ship sank, after which flares and audible signals would guide rescuers to the cylinder.
Van Blaaderen approached the Netherlands’ postal service to support his idea and successfully demonstrated a model in 1914 for the director-general of Posts and Telegraph, but the PTT was reluctant to underwrite the floating safes.
At that time, registered mail in the Netherlands did not include coverage for ocean transport; private marine-insurance companies covered that risk.
In a 1920 compromise, a contract was made between the Netherlands PTT and Van Blaaderen’s company for the latter to build and own the safes, with the government paying a fee per kilogram of goods shipped in the safes.
It soon became clear that the company’s costs exceeded the storage fees, and a new agreement said that senders would pay postage fees plus an additional charge that would be split between Van Blaaderen (5/8) and the post office (3/8).
The Universal Postal Union’s Madrid Congress in 1920 authorized UPU member countries “to charge a surtax, which may not exceed 30 centimes per 20 grams or fraction of 20 grams, for each article which, at the request of the sender, is conveyed in a floating safe placed on board a mail vessel. The surtax is retained by the country of the origin of the article.”
The Van Blaaderen safes were used only on ships of the Nederland Line, between the Netherlands and the Netherlands East Indies.
Those two countries were the only UPU nations to issue stamps for postage on items in floating safes.
A similar service, Simmande Kassaskap (“swimming safe”), was provided by the Swedish Post Office in the Aland Islands, but no stamps were issued.
Anticipating success in his negotiations with the post office, in 1919, Van Blaaderen solicited designs for Floating Safe stamps from five Dutch graphic designers: Carel Adolph Lion Cachet, Leo Gestel, Jan Bertus Heukelom, Piet Wiegman and Jan Ponstijn.
The artists were told to make the Floating Safe designs quite different from the Netherlands postage stamps of the time.
Three designs were chosen, and the colors and denominations of the intaglio-printed stamps were identical on the Netherlands and Netherlands Indies issues.
The first design, by Carel Cachet, shows a floating safe with gulls overhead, in three different colors for the first three values (Scott GY1-GY3): 15¢ slate green, shown in Figure 1, 60¢ rose and 75¢ gray brown.
The other two designs were by Leo Gestel. The first depicts a floating safe with its signal flare in action, used on the 1.50-guilder dark blue, shown in Figure 2, and on the 2.25g orange brown (Scott GY4-GY5).
The second Gestel design shows what the Scott Classic Specialized Catalogue of Stamps and Covers 1840-1940 describes as a “fantasy” of a floating safe, on the 4½g black shown in Figure 3, and the 7½g red (Scott GY6-GY7).
The stamps were printed in sheets of 50 by Johann Enschede en Zonen of Haarlem (one of Holland’s finest printing houses since 1703), and issued Feb. 2, 1921, in the Netherlands and Nov. 1, 1921, in the Netherlands Indies.
Hundreds of thousands of stamps were printed, but only a small fraction were sold. Writing in Filatelie Informatief, Gert Holstege stated that only about 600 pieces of mail were transported in the safes from the Netherlands to the Dutch East Indies, and perhaps 450 in the opposite direction.
The date of Holstege’s article is unknown, but it was probably published in 1989. An Internet search of “Drijvende brandkasten en brandkastzegels” brings up the article’s PDF file, with a picture of a safe.
The stamps were removed from sale Sept. 1, 1923.
Marine insurance stamps of the same designs but with the country names of Curacao and Surinam were printed but never issued. Some were overprinted and used in 1927 as regular-issue stamps (Netherlands Antilles Scott 87-93 and Surinam 132-138).
Attractive, exotic and scarce, a full mint set of the Netherlands marine insurance stamps catalogs at $634.50 unused, $1,500 mint and, rarely known, $2,800 used.