Two historical voyages crossing paths

In one of my previous post, I explained that I am currently working in a project to explain the measurements done by Vening Meinesz, a Dutch civil engineer responsible for high-accurate gravity measurements onboard the Hr. Ms. K18 submarine. He, together with the crew, sailed from Den Helder, Holland to Java, Indonesia. Stopping at harbors along the African, South American and West Australian coast.

At the end of december 1934, the Hr. Ms. K18 left port of Saint Vincent, one of the northern islands of Cape Verde. Cape Verde was also visited by the famous biologist Darwin during his voyage on the HMS Beagle. During this 5 year long voyage Darwin collected many observations that enabled him to establish the evolution theory. A theory that describes the diversity of living creatures and their way of adapting different environments, quite well, if I may say so. 

However this was many years before Vening Meinesz sailed from Saint Vincent. They sailed southwest to the center of the Atlantic Ocean, which is a bit strange if you know that their next port will be Dakar, Africa (which is to the East). Why would they do this? I was looking at some geophysical evidence. It could be that Vening Meinesz would want some nice observations of the mid-oceanic ridge. Remember that the plate tectonic theory was only theorized in the 1960's. 

However I found the direction of the voyage a bit strange. To observe the mid-oceanic ridge best you should sail pure west. Reading the navigation logbook of the voyage I saw that before they reached the ridge, they stayed at a location for one complete day. This was strange because the location had not significant geophysical relevance (just another volcanic landscape). So I decided to read the comments made by Vening Meinesz in his summaries of the voyage. This is what I saw:

Leaving St. Vincent, our route brought us far out into the Atlantic. This loop was due to the crossing of a Dutch areoplane (wow, not aircraft, but areoplane. I like the old times) to the Netherlands West Indies; for providing this plane with the necessary radio-bearings for its position and for giving it indications about the weather, Hr. Ms. K18 was ordered to be stationed for twenty-four hours at a point in the middle of the ocean.

Netherlands West Indies being Curacao. As an Aerospace Engineer, this got my attention. What aircraft? It must be an important crossing, for having the Hr. Ms. K18 have to divert his route. So I did some googling on the web and found the following website.

It was the KLM's maiden voyage to the West Indies. A Fokker F18 (look at the number, both the same!!!) made his 8 day voyage from Amsterdam, Holland to Curacao. The following poster (obtained from the website) shows the route of the Fokker F18:

It states "KLM Christmas Mail Flight to Ned. West-Indie, leaving from Schiphol on 15th of december 1934". The Fokker F18 would eventually land in Curacao on the 22th of December. This would mean that it flew over the Hr. Ms. K18 (number, number) around the 20th, which coincides with the track logbook. If you look closely to the poster (click on it), you can see a small (submarine-shape) figure in the middle of the Atlantic. Could this be the Hr. Ms. K18 with Vening Meinesz onboard? 

The KLM Fokker F18 voyage would be the start of the famous inter-continental airline KLM. Two important voyages in Dutch history crossing paths in space and time, aiding each other. Hr. Ms. K18 provided bearings and weather reports and for the sake of the story, maybe the Fokker F18 transported a Christmas letter for Vening Meinesz which he received on his later visits in South America. The paragraph of his comments did not end and neither did his voyage:

The Navy had consented that the ship, once this duty fulfilled, continued its route for reaching the area of the Mid Atlantic rise and then returned by a different route towards the next port, Dakar. By regularly diving once during the day and once during the night a valuable series of observations was obtained over the whole trip. The soundings over the Mid Atlantic rise showed an irregular topography, suggesting a volcanic landscape. The approach to Dakar provided the writer with a further coastal gravity profile.

The mentioned irregular topography is the old volcanic landscape created by plate motion (not known in Vening Meinesz time), where the age of the landscape decreases towards the center of the rise. I complete this post with the observations of Vening Meinesz (gravity and soundings), such that you can see the scientific value of this voyage. 

In the end I think this crossing of voyages is remarkable and should be remembered.