Hydraulic cylinder seems to be the correct term for what I know of as a hydraulic ram. It is a linear actuator that revolutionized the design of farm and construction equipment.
 |
| 20140806 0241c |
Update: a video about hydraulics.
Above is the ram for the boom-stick joint at the top of the Deere excavator in the following photo.
The chrome-plated steel piston rod passes through a seal gland in the cylinder head. The following diagram illustrates that the piston rod (red) connects to a piston (orange).
The two blue rectangles indicate ports where hydraulic hoses would attach. Both single-acting and double-acting rams have the dark blue connection. When a valve opens and allows fluid to flow from the hydraulic pump to the dark blue port, the piston rod is shoved out of the cylinder or extended. For a double-acting cylinder, which would also have a hose connected to the the light-blue port, the value would have to connect that hose to the hydraulic reservoir to allow fluid to drain out of the head port while fluid is entering the base or cap port. When the valve connects the head port to the pump and the cap port to the reservoir, the piston rod is pulled in or retracted. (A single-action ram can't force the rod to be retracted.)
The first front loader my Grandpa got for his Ford tractor had single-acting rams. The valve connected the port at the bottom to the pump supply to raise the loader. To lower it, the valve connected the port to the reservoir, and the loader was forced down by gravity. Note that a single-action cylinder does not need a seal gland because there is no oil on the head side of the piston. But now that manufactures have developed the machine tools necessary to build seal glands they are economic enough that the only rams I have seen the last few decades are double-acting.
When I was a kid in the 1960s, the excavators that I watched work had friction drums and cables instead of hydraulics.
I believe I was seeing backhoes on a tractor in the 1960s. These had a power shovel mounted on the back of a tractor and a loader on the front.
I didn't know they made face shovels this small by the time they quit using steam. I'm used to seeing mining shovels being quit large.
This is like the cable excavators I remember seeing when I was a kid in the 1950s. The bucket is rigid. To unload it, the boom has to be raised by pulling on the upper cable and the stick extended by reeling out the lower cable.
And excavators kept growing.
Above is the ram for the boom-stick joint at the top of the Deere excavator in the following photo.
The chrome-plated steel piston rod passes through a seal gland in the cylinder head. The following diagram illustrates that the piston rod (red) connects to a piston (orange).
The two blue rectangles indicate ports where hydraulic hoses would attach. Both single-acting and double-acting rams have the dark blue connection. When a valve opens and allows fluid to flow from the hydraulic pump to the dark blue port, the piston rod is shoved out of the cylinder or extended. For a double-acting cylinder, which would also have a hose connected to the the light-blue port, the value would have to connect that hose to the hydraulic reservoir to allow fluid to drain out of the head port while fluid is entering the base or cap port. When the valve connects the head port to the pump and the cap port to the reservoir, the piston rod is pulled in or retracted. (A single-action ram can't force the rod to be retracted.)
The first front loader my Grandpa got for his Ford tractor had single-acting rams. The valve connected the port at the bottom to the pump supply to raise the loader. To lower it, the valve connected the port to the reservoir, and the loader was forced down by gravity. Note that a single-action cylinder does not need a seal gland because there is no oil on the head side of the piston. But now that manufactures have developed the machine tools necessary to build seal glands they are economic enough that the only rams I have seen the last few decades are double-acting.
When I was a kid in the 1960s, the excavators that I watched work had friction drums and cables instead of hydraulics.
 |
| http://en.wikipedia.org/wiki/File:Old_excavator.jpg |
I believe I was seeing backhoes on a tractor in the 1960s. These had a power shovel mounted on the back of a tractor and a loader on the front.
 | |
| 20140811 0469 |
But it took longer for hydraulic technology to advance enough to handle the horsepower of an excavator. In an excavator, all of the horsepower of the diesel engine is used by just hydraulic pumps. Even the tracks are run by hydraulic motors. According to Wikipeida, the engine would drive a couple of high-pressure (up to 5000 psi) pumps for the actuators and a lower pressure pump (700 psi) to control the actuator valves so that the operator valves required less effort to operate. Hydraulic technology has advanced enough that even huge mining shovels have converted from cable to hydraulic cylinders. The current largest hydraulic excavator is the 4500 hp CAT 6090. A video of the CAT 6060 provides a better explanation of these beasts.
My father-in-law worked for a company that built drilling rigs on trucks. I remember him telling about converting the rigs from cables to hydraulic cylinders. They started having field support problems because the hydraulic force was so powerful it was bending the boom. They had to completely redesign the unit to work properly with hydraulics.
 |
| Tool Time Tricks posted Hydraulic power in motion . See how an excavator arm really works! This engineering visualization breaks down the working of an Excavator hydraulic arm system—showing how fluid pressure drives cylinders, controls motion, and delivers massive digging force with precision. |
My father-in-law worked for a company that built drilling rigs on trucks. I remember him telling about converting the rigs from cables to hydraulic cylinders. They started having field support problems because the hydraulic force was so powerful it was bending the boom. They had to completely redesign the unit to work properly with hydraulics.
Some photos of plowing with a moldboard plow show how a lever was used to raise the plow at the headland before hydraulic circuits were added to tractors.
 |
| Kirby Lamp posted Dennis DeBruler I was surprised that an old-looking loader has double-acting hydraulic rams. I remember my grandfather's first loader had just a single acting ram because creating a seal around the ram to apply downward pressure had not been perfected. And because gravity did a good job of lowering the loader.Kirby Lamp grandpa had that loader on a m that i have now never have taken all the bracket of the tractor for some reason. [The "m" would have been a Farmall M tractor.] |
 |
| 20140801 0055 |
The top and bottom cables each have their own winch.
When the operator pulls back on the control for the top cable so that
the cable is reeled in, it is rather obvious that the boom will go up.
And if the bottom cable is reeled in, the bucket will go towards the
operator. What is not so obvious to me is that when the bottom cable is
reeled in, the boom also goes up. If the operator wants the bucket to
dig a flat trench, he needs to reel out the top cable as the bottom
cable is reeled in. You can watch a video of this shovel and another in operation.
Backhoes were not developed until the 20th Century. But steam-powered face shoves were developed in the 19th Century. Cable driven face shovels grew really big because they were used for strip mining. The Captain (Marion 6360) is an example of a more modern large shovel. In fact, large face shovels are still made with cables, but I can't find my notes on that.
 |
| Anders Eriksson posted Ruston-Bucyrus 19-RB at a vintage machinery meeting in Sweden last summer. |
 |
| Chuck Seelen posted, cropped Garret Wilson That's beautiful, I'm a huge fan of those PL undercarriages too! |
 |
| Ben Stalvey posted So for those asking if Manitowoc made cable backhoe versions. Here is one several models were used for them. 3000. 3500s, 3900 even 4600s. John Fraser Backhoe or Back-actor on a friction clutch and brake machine could be a difficult piece of equipment, depending on the terrain. I have used it a few times and it was a particular challenge when excavating blasted rock. John Suckoe 3900 max 4600 on barge |
Lucibello Heavy Equipment photography posted three photos with the comment:
Northwest 9570DA, which was recently restored by Boro Sand and Stone of Massachusetts. This machine, to my knowledge, is the last 9570DA with the original backhoe attachment installed. Before being restored this machine was set up as a sauerman yarder up in Maine. Now for some background information. Back in later half of the 1960s hydraulic excavators where starting to gain traction in the North American market. This lead to domestic cable equipment equipment manufactures coming up with ways to incorporate this new technology. One of those ways was Northwest DA line of cable backhoes. This line consisted of the 41DA, 50DA, 95DA, 9570DA, and 190DA. All of this cable backhoes where equipped with a hydraulic actuated bucket, which gave the operator greater control compared to traditional cable backhoes which had a fixed bucket. One neat thing Northwest did was to extend the dog bone for the bucket past the hinge point and tie it into the cable pull back snatch block. What this did was give the machine a greater breakout force, which no hydraulic machine of the time could match. This "power pull" design gave the 95DA, the precursor to the 9570DA, a total breakout force of 47 tons! The 9570DA was equipped with a four yard bucket and roughly fifty units where sold.
Dutch Baldwin: That exact machine in crane mode is down by me in southern Maryland sitting in a guys front yard. Looks like it’s freshly restored.
 |
| 1 |
 |
| 2 |
.jpg) |
| 3 Hans Burger shared Dave Johnson: 9570 da I liked this machine, took a couple days to get used to the hydraulic bucket. |
John W. Coke posted two photos.
I don't like profile videos, especially of horizontal subjects, but this was a better vantage point.
 |
| 1 |
 |
| 2 |
 |
| Screenshot, found the post. Zagray museum May 4, 2019, Connecticut |
 |
| Screenshot |
 |
| Historische Baumaschinen posted Expedition to the Animal Kingdom: The Priestman Program 1968 Daniel Krähenbühl shared |
%20Facebook.png) |
| Gladowski posted a Facebook reel |
 |
| Paul Mandra commented on Mike Gladowski's post |
 |
| Hans Burger posted |
 |
| Street View, Jul 2023 via Dennis DeBruler |
Bradley Haines posted video and photos of both backhoe and face shovels.
 |
| 1 of 4 photos posted by Missouri's Historic Highways 07-24-1953 Rt. 65, South Cry Sac Creek Greene County Dennis DeBruler: Thanks. I have been looking for years for a photo of an excavator before hydraulic controls were developed. |
.jpg) |
| Leo Odijk posted Koehring dieplepel. Daniel Krähenbühl shared |
Backhoes were not developed until the 20th Century. But steam-powered face shoves were developed in the 19th Century. Cable driven face shovels grew really big because they were used for strip mining. The Captain (Marion 6360) is an example of a more modern large shovel. In fact, large face shovels are still made with cables, but I can't find my notes on that.
 |
| Screenshot @ -3:50 This rail mounted steam shovel is believed to be the only working example of it's type in the World. It was recovered in 1977 by Ray Hooley from a chalk pit in Arlesey, County Bedfordshire which supplied a cement works. It was used as a face shovel and was one of two that worked the quarry until the 1920s. Two examples of this machine worked the quarry and both were abandoned when the pit closed in the 1930's. during WW2 the shovel on the upper level was recovered for scrap but the one on the lower level was abandoned due to being submerged and hard to reach. After recovery in 1977, the steam shovel was restored at Ruston's Lincoln works by 1980, and was given on permanent loan to the museum of Lincolnshire life. By 2008 after the machine falling into disrepair, Ray Hooley gave the shovel to the Vintage excavator trust located at Threlkeld quarry in Cumbria who have restored it to it's former glory with the assistance of a National lottery. |
 |
| Screenshot @ -3:59 |
I didn't know they made face shovels this small by the time they quit using steam. I'm used to seeing mining shovels being quit large.
 |
| Barry Thornberry posted |
 |
| Ben Stalvey posted Nothing like a old Manitowoc Speed shovel Robert MacKenna Beautiful 3000 Jackie Mensch Never ran a Manitowoc. B&E |
 |
| Jesus Cortes Manzanares posted Cananea sonora México [This shows that the cranes used steam power well after the development of the internal combustion engine. Note only is the truck small for mining, it has no cab!] |
This is like the cable excavators I remember seeing when I was a kid in the 1950s. The bucket is rigid. To unload it, the boom has to be raised by pulling on the upper cable and the stick extended by reeling out the lower cable.
 |
| Barry Thornberry posted [The old and the older. Big Brutus "The world's biggest electric shovel." I didn't even know there was strip mining in Kansas.] |
 |
| Facebook Reel The first prototype was built in 1948. |
 |
| Facebook Reel |
 |
| Andre Tardif shared [Note the skid loader under the regular sized excavator.] |
And excavators kept growing.
 |
| Screenshot This machine is called CAT 6015B and it is the largest of its kind standing at over 70m (230') tall |
 |
| Mining #Shorts posted Battle of the giants... - Top picture is a Komatsu PC8000. Bottom pic is a Liebherr R 9800. Both serve the same purpose: moving as much earth as possible during a shift. One, the PC8000, was designed in the 1990s. The other, the R 9800, entered the market in 2010. In terms of specs, the Liebherr takes the edge: 773 tonnes vs 810 tonnes 47.5 m³ vs 42 m³ Equivalent horsepower. When it comes to electrification, the Komatsu PC8000 clearly leads, with many units running electric, while the R 9800 still lacks a defined electric variant. The PC8000 also leads in shovel units delivered, while fewer than 10% of R 9800 units were built as shovels. Most operators who ran the PC8000 rate it highly. Same story for those on the R 9800. There’s no real battle here. They complement each other. |
 |
| Mining #Shorts posted The Liebherr R 9100 G8 is here - Liebherr is moving its next-generation 100-tonne class excavator into full-scale production, following an extended validation phase in real mining conditions. The R 9100 G8 has completed pre-series testing between September 2024 and December 2025 in Indonesia, where it was deployed on overburden removal and truck loading duties. Results from that program are now shaping the machine’s industrial rollout. In the field, the excavator averaged 448 bank cubic metres per hour, equivalent to roughly 923 tonnes per hour, while maintaining a 92% availability rate. Fuel consumption averaged 68 litres per hour, about 23% lower than comparable 100-tonne machines on the same site. Over a full year, that translates into savings of up to 100,000 litres of diesel compared to the previous generation. At peak performance, the machine reached 771 bcm per hour during controlled testing, exceeding site targets by nearly 30%. The G8 remains powered by a 565 kW Liebherr diesel engine, paired with an updated hydraulic system and the company’s Power Efficiency management platform. Operating weight sits between 112 and 116 tonnes depending on configuration, with bucket capacities around 7 to 7.5 cubic metres. Beyond raw output, the focus shifts to cost per tonne. The machine introduces redesigned maintenance systems with 250-hour service intervals, integrated digital monitoring via IoMine, and a 360-degree camera setup to improve operator awareness. With validation complete and performance targets exceeded, Liebherr is now positioning the R 9100 G8 as a core product in its mining lineup. |
 |
| Isnawatul Jannah posted The Bucyrus RH400 (TEREX), now owned by Caterpillar, is said to hold the title of the world's biggest hydraulic excavator. This monster is a front shovel excavator and weighs in at around 980 tonnes. This mine chewer has an undercarriage width of 8.6 meters and crawler length of 10.98 meters. Just one scoop of the shovel can remove 45 cubic meters of material. With a crowd force of 3,300 kN and a breakout force of 2,400 kN we defy any unfortunate rock face to resist this machine. The Bucyrus RH400 is powered by two 16 cylinder Cat 3516B or Cummins QSK60 diesel engines. |
 |
| Facebook Reel |
Likewise, the cable shovels have become big.
 |
| Mining #Shorts posted Have you ever heard of the P&H 4100TS? - Of course, you’ve heard of the P&H 4100, the XPB and XPC variants. But what about the 4100TS? This model was delivered in late 1998 to Suncor, built for the intense conditions of Canada’s oil sands. The 4100TS came with a 58 yd³ dipper capable of moving 100 tons and rode on extra-wide pads designed to support its 1,500-ton weight on soft ground. The pads measured 138 inches wide. Very few TS variants were ever produced. This underscores how operations in the Canadian oil sands demanded highly specific, custom specifications, creating some of the most unique machines in the mining industry. Steve Day: The TS has been dropped but the shovel is very much in production and is the main shovel in the oilsands it just got renamed as the 4100 C BOSS or 4100 C BOSS A/C depending what electric motors it is fitted with. BOSS stands for Big Oil Sands Shovel. Brian Hahn: Steve Day Big Oil Sands Shovel was adopted when they went to the C series shovels. It was so that they could keep the well recognized BOSS name. It was originally the B (series) Oil Sands Shovel. |
 |
| Dallas Miller commented on the above post That's cute. |
 |
| safe_image for A Shifting Fluid Power Industry "The transition to electrification will bring about a need to rethink the design of traditional hydraulic systems." [They replace hydraulic fluid with a belt on a pulley system in the cylinder. The belt is driven directly by an electronically controlled motor. And the motor can act as a generator when a load is lowered. And the article says that hydraulic cylinders can't pull as well as they can push, but their new cylinder design can do both with equal strength. They don't mention it, but it seems that stringing wires rather than hoses around a machine would reduce maintenance issues. Wires generally don't have a problem with leaks.] |
