Combine the raisins and water in a 3-quart saucepan and bring to a boil. Boil, uncovered, for 5 minutes, then remove from the heat and add the shortening. Cool to lukewarm. Sift the flour, sugar, baking soda and salt together into a mixing bowl and add the eggs, walnuts and raisin mixture. Stir until just moistened. Spoon the batter into 6 greased (1-lb) vegetable cans. Bake in a preheated 350 degree F. oven for 1 hour or until a cake tester or wooden pick inserted in the center of each loaf comes out clean. Cover with aluminum foil for the last 15 minutes of baking to prevent overbrowning. Cool in the cans for 10 minutes before turning out onto wire racks to cool to room temperature.