diff --git a/src/main/java/org/gcube/contentmanagement/blobstorage/service/operation/Operation.java b/src/main/java/org/gcube/contentmanagement/blobstorage/service/operation/Operation.java
index bdf1d0e..adb9c50 100644
--- a/src/main/java/org/gcube/contentmanagement/blobstorage/service/operation/Operation.java
+++ b/src/main/java/org/gcube/contentmanagement/blobstorage/service/operation/Operation.java
@@ -41,7 +41,7 @@ public abstract class Operation {
 	private Monitor monitor;
 	private boolean isChunk;
 	String backendType;
-	TransportManager transport;
+	protected static TransportManager transport;
 
 	public Operation(String[] server, String user, String pwd,  String bucket, Monitor monitor, boolean isChunk, String backendType, String[] dbs){
 		this.server=server;
@@ -384,8 +384,7 @@ public abstract class Operation {
 	protected TransportManager getTransport(MyFile myFile) {
 		if(Objects.isNull(transport)) {
 			TransportManagerFactory tmf= new TransportManagerFactory(server, user, password);
-			TransportManager tm=tmf.getTransport(backendType, myFile.getGcubeMemoryType(), dbNames, myFile.getWriteConcern(), myFile.getReadPreference());
-			return tm;
+			transport=tmf.getTransport(backendType, myFile.getGcubeMemoryType(), dbNames, myFile.getWriteConcern(), myFile.getReadPreference());
 		}
 		return transport;
 	}