Most legumes in bulk are shipped in closed hoppers with Pnuematic unloading. Door bottom types were used before Pnuematic Unloading came into use. The type processing would determine the type cars used for shipping. Those processed into canned goods, bags, sacks et. are shipped in boxcars.
Legumes are used as foodstuff for humans and animals. More information is included under each type.
Here are some of the types of legumes and their varieties.

The legume family, of which all beans, peas, lentils, and peanuts are a part, is one of the largest in the plant kingdom. Because of this and the many thousands of years of development and cultivation that man has given them on several continents, the variety of edible legumes available to us is huge. Both the appearance and the names of these varieties are colorful and varied. They range from soybeans from the Orient, to field peas, commonly found Southern U.S. Their color can range from a clean white, to deep red, dull green to flat black with thousands of mixtures and patterns of colors.
In spite of this incredible variety of names and colors, legumes are largely interchangeable in cooking usage, although some dishes just wouldn't be the same if a different type were used. Below is a partial list of some of the more commonly eaten bean varieties here in the U.S.

BLACK BEAN: Also known as "turtle beans", these small, dark brownish-black, oval-shaped beans are well known in Cuban black bean soup. They are very commonly used in Central and South America and in China. They tend to bleed very darkly when cooked so they are not well suited to being combined with other beans, lest they give the entire pot a muddy appearance. Sold both fully cooked in cans or raw in bags, sacks etc. Most often sold raw in small plastic bags in grocery stores.

BLACK-EYED PEA: Although there is tremendous variation among the many varieties of field-peas eaten throughout the Southern United States, it is black-eyed peas that are the most commonly known nationwide. The coloring of field-peas is as varied as the rest of the legume family, with black-eyed peas being small, oval shaped with an overall creamy color and, of course, their distinctive black-eye. Dried field-peas cook very quickly and combine very tastily with either rice or cornbread. Sold both fully cooked in cans or raw in bags, sacks etc. A traditional meal on New Years Day is Black-Eyed peas, at least in the Southeast.

CHICKPEA: Also known as the "garbanzo bean" or "cecci pea" (or bean), it tends to be a creamy or tan color, rather lumpily roundish and larger than dried garden peas. Many have eaten chickpeas, even if they've never seen a whole one. They are the prime ingredient in hummus and falafel and are one of the oldest cultivated legume species known, going back as far as 5400 B.C. in the Near East. Chickpeas tend to remain firmer when cooked than other legumes and can add a pleasant texture to many foods. Most often sold fully cooked in cans in grocery stores.

KIDNEY BEANS: Just like the rest of the family, kidney beans can be found in wide variety. They can be white, mottled or a light and dark red color in their distinctive kidney shape. Probably best known here in the U.S. for their use in chili, they figure prominently in Mexican, Brazilian and Chinese cuisine. Sold both fully cooked in cans or raw in bags, sacks etc.

LENTILS: Lentils are an odd lot. They don't fit in with either the beans or the peas and occupy a place by themselves. Their shape is different from the other legumes being roundish little discs with colors ranging from muddy brown, to green to a rather bright orangish-red. They cook very quickly compared to the larger beans and have a distinctive flavor. They are much used in Far Eastern cuisine from Indian to Chinese. Sold both fully cooked in cans or raw in boxes, bags, sacks etc.

LIMA BEANS: In the Southern U.S., they are also commonly called "butter beans". They are one of the most common legumes found in this country in all manner of preservation from the young small beans to the large fully mature type. Their flavor is pleasant, but a little bland. Their shape is rather flat and broad with colors ranging from pale green to speckled cream and purple. Sold both fully cooked in cans or raw in bags, sacks etc. "Butterbean" sandwiches are sometimes consumed in the Southeast.

MUNG BEANS(Bean Sprouts): Best known here in the States in their sprouted form. They are quite common in Indian and other Asian cuisines and are a close relative of the field peas grown throughout the Southern United States. Their shape is generally round, fairly small with color ranging from a medium green to so dark as to be nearly black. They cook quickly and soaking is not generally needed. Sold both fully cooked in cans or raw loose at the veggie counter.

PEANUTS: The peanut, commonly known outside the U.S. as the "groundnut", is not actually a nut at all, but a legume. They are another odd species not much like the more familiar beans and peas. Whatever their classification peanuts are certainly not unfamiliar to U.S. eaters. Peanuts have a high protein percentage and even more fat. They are one of the two legume species commonly grown for oilseed in this country. Peanuts can be boiled, toasted, roasted, baked and eaten raw. Salted or unsalted, shelled or unshelled, and are also used to make peanut butter. Probably one of the best known snack foods in the Southeast. Sold in bulk, boxed, canned, sacks, bags in many places. Raw peanuts are dryed, stored and sold in bulk to other processors.

Picture of a modern Peanut Processing Plant

PEAS, GREEN OR YELLOW: More often found as green split peas though whole peas can sometimes be found. The yellow variety is now somewhat uncommon. Probably best well known in split pea soup, particularly with a smoky chunk of ham added. They are also commonly used in Indian cuisine, particularly dals. Whole peas need soaking, but split peas can be cooked without soaking. Split peas and pea meal makes an excellent thickener for soups and stews. Sold in cans, bags etc in grocery stores.

PINTO BEANS: Anyone who has eaten Tex-Mex food has probably had the pinto bean. It is one of the most commonly eaten beans in the U.S., particularly in the Southwestern portion of the country. Stereotypically bean shaped, it has a dappled pattern of tans and browns on its shell. Pintos have a flavor that blends well with many foods. When ground together with white or navy beans they make my favorite home-made version of falafel. Sold both fully cooked in cans or raw in bags, sacks etc.

SOYBEANS: It is by far the legume with the highest protein content in commercial production as well as being the other legume oilseed alongside the peanut. The beans themselves are small, and round with a multitude of different shades. Although the U.S. grows a very large percentage of the global supply, we consume virtually none of them directly. Most of them go into cattle feed, are used by industry or exported. What does get eaten directly has usually been processed in some fashion. Soybean products range from tofu, to tempeh, to textured vegetable protein (TVP) and hundreds of other uses. They don't lend themselves well to just being boiled until done and eaten the way other beans and peas do. Processed soy-beans are sold in grocery stores and in bulk to other processors.