The building of the Dutch merchant ships Luit. Admiraal Callenburg, Pomona and Jan van Harwegen at Vlaardingen according to the Dutch newspaper Schiedamsche Courant dated Monday 7 May 1855

Vlaardingen, 3 May. Today is at the yard of H. Drop de Zeeuw with success the brig ship Luit. Admiraal Callenburg of 100 measured lasten launched on behalf of the company with as directors Gebr. Den Breems and master P.L. Schep. Afterwards is the keel laid down of a schooner of 70 lasten on behalf of the company of M. den Breemsz Jz to be named Jan van Harwegen. The same day was at the yard of S. van Gijn en Zn. the keel laid down of the schooner Pomona of 55 measured lasten on behalf of the company of J. van Harwegen en den Breems.