Marine and subsea slip rings
Moog Model 173 marine and subsea slip ring
Electro-optical hybrid marine rotary unit combining up to 52 fibre passes with high-voltage power.
Key specifications
| Voltage (max) | 7,400 V |
|---|---|
| Fibre channels (max) | 52 |
Summarised in our own words from Moog Inc.'s published data; series maxima, individual models vary. Last checked 2026-10-29. Source 1 · Source 2
Notes on this data
Up to 720 A total.
Specify Motion is not affiliated with Moog Inc.. Moog and Model 173 are used only to identify the product. Comparisons use published figures; always confirm against the current datasheet.
Typical applications
Alternatives that meet or exceed these figures
Engineers often come to us with a Moog part number and leave with an alternative that is easier to source, quicker to deliver or a better fit for the machine. These series from our supply network is the closest match on published figures.
Heavy-duty carbon-brush slip rings for very high current and voltage, with copper-graphite power rings and precious-metal signal rings. Large and heavy by design, but straightforward to maintain.
| Published maximum | Model 173 | BHR Series Frameless Type (Carbon Brush) |
|---|---|---|
| Circuits | — | 76 |
| Current per circuit | — | 500 A |
| Speed | — | 10 rpm |
| Voltage | 7,400 V | 20,000 V meets or exceeds |
| Fibre channels | 52 | — |
Figures are the highest published for each series and are not always measured the same way. A higher figure is not automatically a better choice: mounting, duty cycle, feedback, connectors and approvals matter too. An engineer will check the fit against your application before recommending anything.
What a marine and subsea slip ring is
A marine slip ring is a rotary joint built to survive salt air, spray, condensation and, for subsea versions, immersion and external pressure. The electrical design is conventional, with power, signal and data rings, but the housing uses corrosion-resistant materials such as stainless steel or marine-grade aluminium, robust shaft seals and suitable connectors. Subsea units are commonly oil-filled and pressure-compensated so internal pressure matches the surrounding water, which keeps seals working at depth.
When engineers choose a marine and subsea slip ring
Choose a marine design for deck winches, cranes, mooring and cable reels on ships and offshore platforms, and for ROVs and other subsea vehicles. A standard industrial unit in an enclosure is sometimes adequate in sheltered locations, but salt and condensation shorten life quickly. The trade-offs are size, weight, cost and lead time. For subsea work, compensated designs add complexity but avoid relying on seals to hold back full pressure. Fibre and high-voltage channels are often needed alongside power.
How to specify the Moog Model 173
Send these with your enquiry and an engineer can confirm the right Model 173 variant or an equivalent:
- Location: deck, splash zone or subsea, with depth rating (m)
- Ingress protection (IP code) and pressure compensation method
- Housing and shaft materials
- Power circuits, current and voltage (A, V)
- Data or fibre channels
- Speed (rpm) and duty
- Connectors, glands and cable types
Common mistakes to avoid
- Using an industrial slip ring in a box on deck, where condensation forms inside
- Mixing metals that corrode galvanically in seawater
- Overlooking high-voltage clearance on winch slip rings feeding subsea power
- Not specifying compensation fluid and service intervals for oil-filled designs
Moog Model 173: frequently asked questions
What is the Moog Model 173?
Electro-optical hybrid marine rotary unit combining up to 52 fibre passes with high-voltage power. Published series figures include voltage 7,400 V, fibre channels 52. It is made by Moog Inc.; Specify Motion can help source it or propose an equivalent.
Who makes the Moog Model 173?
The Moog Model 173 is made by Moog (Moog Inc.) and is listed here for engineers comparing options. Specify Motion is not affiliated with Moog Inc.; brand names are used only to identify the product.
What is the voltage of the Moog Model 173?
The published series maximum voltage is 7,400 V. Individual models and sizes in the Model 173 range vary, so check the exact variant against your duty cycle, mounting and environment, or ask our engineers to confirm the right size for you.
Is there an alternative to the Moog Model 173?
Yes. On published figures, BHR Series Frameless Type (Carbon Brush) is the closest match from our supply network. An engineer confirms the fit against your application before recommending anything.
What does pressure-compensated mean for a subsea slip ring?
A pressure-compensated slip ring is filled with an insulating oil and linked to a flexible bladder or piston that lets the surrounding water pressure act on the oil. Inside and outside pressures stay nearly equal, so seals only have to keep fluid in, not resist full depth pressure. This is common for ROV and deep-water equipment because it makes depth rating far less dependent on wall thickness.
Is IP68 enough for a marine slip ring?
IP68 means protected against continuous immersion under conditions agreed by the manufacturer, so the actual depth and duration must be stated alongside it. It does not cover corrosion, UV, salt fog or pressure cycling. For deck equipment, specify materials and sealing for salt spray and condensation. For subsea, give the rated depth and test pressure, not just an IP code.
Further reading: Waterproof and subsea slip rings · How to select a slip ring · Slip rings
Other marine and subsea slip rings series
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