INTRODUCTION 



Successful application of an air bubbling technique for prevent- 

 ing ice formation dui-ing the fall of 195^ enabled the Military Sea 

 Transpoi'tatlon Service to e:ctend the shipping season at Thule, Green- 

 land. The normal shipping season extends from early Jvily to early 

 October. Shipping during the first half of July is usually dependent 

 on icebreaker escort; shipping is ordinarily terminated prior to 

 initial ice formation in autumno 



Adaptation of a method originally developed in Scandinavian coun- 

 tries for prevention of fresh-water freezing permitted maintenance of 

 an ice-free area (polynya) adjacent to De Long pier despite normal 

 ice formation in the surrounding waters of North Star Bugt (Bay). 

 Safeguarded against becoming frosen-in at the pier, ships of the 

 supply convoy remained at Thule until 25 October 1958 - the latest 

 date on which MSTS had ever operated in such a northerly location. 

 Success of the temporary installation prompted the Commander Military 

 Sea Transportation Service Atlantic (COMSTSLATIT) to formulate plans 

 for the establishment of a permanently installed bubbling system at 

 De Long pier. 



In the fall of 1959, the U. S. Navy ^ydrographic Office was 

 requested to conduct oceanographic studies concurrently with the 

 operation of the system in order to obtain infojrmation on physical 

 processes impeding ice fonnation and growth in the bay. The over- 

 all operation was dubbed "Project Polynya", 



NORTH STAR BUGT 



North Star Bugt, approximately 3 square miles in area, recedes 

 about I-I/2 miles northeastward between Astro Pynt and Mount Dundas 

 on the southern shore of Wolstenholme Fjord, The entrance of the 

 bay, about 3/^ mile wide, is narrowed by De Long pier and. a causeway 

 which extend approximately O.k mile west-northwestward from Astro 

 Pynt. The pier, 1,000 feet in length and 50 feet in width, adjoins 

 the causeway and is parallel to it. Inside the entrance, the width 

 of the bay increases to about 1 mile„ 



POLYNYA INSTALLATION 1959 



Urider the supervision of MSTSLANT, Canadian Underwater Demolition 

 Unit BRAVO began installation of the bubbling system in North Star Bugt 

 early in September 1959* Briefly, the system consists of perforated 

 submarine polyethylene pipes which serve to conduct compressed air to 

 the bottom of the bay and distribute it in the form of bubbles over a 

 wide area (see Figure 1). An auxiliary alcohol-injection system Is 

 utilized to prevent or eliminate ice formation within the pipes. 



Installation v;as completed on 27 September. Equipment was inter- 

 mittently tested until appreciable ice began to form in the bay on 

 7 October, at which time full operation was begun. 



