Hatch locks operable from both sides?

twistedtree · Oct 31, 2019

I'm trying to find hatch locks that are operable from both sides of the hatch. These are for the hatches in the cockpit floor, leading to the laz below, and are commonly found on many boats. They typically have handles that fold flush to the deck, and that flip up and turn to open the hatch. But they all seem to be operable from the outside only, preventing escape from inside the laz. The dive boat fire in California has me carefully reviewing escape paths on our boat, and getting out via the laz is an important route. Except you can open the hatch from inside.

So the question is whether anyone has or has seen latch mechanisms like this that are operable from both sides? We have found one with an emergency release and have ordered a sample, but for a variety of reasons I an skeptical about how well it will work in practice. Worst case we will station a tool by the exit so the lock can be disassembled, but that's not a desirable approach.

I'd appreciate any leads, and will be scouring FLIBS and METZ over the next days and month..

O C Diver · Oct 31, 2019

That's going to be a tough one.

Maybe a simpler approach would be to configure the catch plate that the arm engages, so that it's easily swung away from the arm of the latch. My hatches have the arm catching the hatchway frame. It would be easy to shorten the arm so that it just misses the frame. Then mount a plate with one screw to the bottom of the frame that the arm can catch. In an emergency, the plate could be swung away without a tool.

Ted

twistedtree · Oct 31, 2019

O C Diver said:
That's going to be a tough one.

Maybe a simpler approach would be to configure the catch plate that the arm engages, so that it's easily swung away from the arm of the latch. My hatches have the arm catching the hatchway frame. It would be easy to shorten the arm so that it just misses the frame. Then mount a plate with one screw to the bottom of the frame that the arm can catch. In an emergency, the plate could be swung away without a tool.

Ted

It is indeed proving tough to find, and I'll throw your suggestion into the pile of possible approaches in the absence of a ready-made solution.

wkearney99 · Oct 31, 2019

Under what circumstances are you going to be inside a lazarette that's been closed? Or is this a pass-through area?

With many cam style locks you could, conceivably, fabricate a longer lever-handle on the opposite end of the cam. Brute force on it would very likely overcome any resistance from the flush handle above, breaking it. If this were an emergency that wouldn't matter. The downside being some hatch pulls rotate 180 to allow the cam 'tongue' to clear the catch in the frame. Making the opposite end longer would require making a only a 90 turn to get the catch clear without the longer 'handle' getting in the way.

But for a pass-through area it would seem like an actual two-sided door locking assembly would be a better choice.

Northern Spy · Oct 31, 2019

I'd contact Freeman Marine with your concerns. They might be interested in adapting their design as others may be thinking the same.

Shrew · Oct 31, 2019

OK, so semi-related, so I apologize for the semi-hijack. I was in the engine compartment about a month ago and needed the Admiral to drop in the deck hatches to move around some furniture while I was down there.

That is not a great feeling. I think psychologically knowing I couldn't open the hatches while I was down there was disturbing. I have never been claustrophobic, and was surprised how uncomfortable I felt.

twistedtree · Oct 31, 2019

On our boat, the clearest alternate exit path from the lower level is out thru the ER, into the Laz via a door, then out to the cockpit thru the hatches in question. Escape routes will of course vary boat to boat. But if the stairway to/from the lower level is blocked, out thru the ER and laz is the only alternate path. The main electrical panel is at a landing in the stairwell, and the stairs emerge onto the main deck adjacent to the galley. So there are too likely fire origination points that could block the stairs.

We are also considering floor hatches in the ceilings of the lower level rooms, but they would emerge into roughly the same place as the stairs, so I think provide little incremental value. So right now I think there is much more gain by figuring out good ways to get out thru the laz hatch.

BTW, I would encourage everyone to identify AND TEST you alternate exit paths. Be sure you can actually get out of them. We aren’t as young and agile as we all used to be.

Shrew · Oct 31, 2019

I'm sure the M/V Conception fire has a lot of people thinking along these lines. We were discussing how the guest berth and head hatches are not 'egress hatches'. This means if the main stairs were blocked, guests would need to head forward into the master to escape through that hatch. My wife's response "Would guests know to do that?"

Another bullet point for the guest tour and lecture.

rslifkin · Oct 31, 2019

Shrew said:
OK, so semi-related, so I apologize for the semi-hijack. I was in the engine compartment about a month ago and needed the Admiral to drop in the deck hatches to move around some furniture while I was down there.

That is not a great feeling. I think psychologically knowing I couldn't open the hatches while I was down there was disturbing. I have never been claustrophobic, and was surprised how uncomfortable I felt.

That's an interesting point. What keeps your engine room hatches closed, out of curiosity? In my case, the main engine room hatch is just held down by gravity, so it could be pushed open from inside. The secondary access hatches can't be, however, as the carpet needs to be peeled back to expose them.

wkearney99 · Oct 31, 2019

I saw your ER door on your blog site. Any pix of the laz hatches?

Excellent points about testing emergency exit procedures. It's important to stress the priority is to GET OUT immediately. Not get out with stuff/clothes or without some risk of injury. OUT. NOW.

twistedtree · Oct 31, 2019

rslifkin said:
That's an interesting point. What keeps your engine room hatches closed, out of curiosity? In my case, the main engine room hatch is just held down by gravity, so it could be pushed open from inside. The secondary access hatches can't be, however, as the carpet needs to be peeled back to expose them.

Good point. They might be a possible escape route, but subject to rugs and random furniture above. So I don’t think I’d flag it as the primary path. Plus the removable floor sections are pretty big and I expect quite heavy. On our boat they are meant strictly for engine removal and are not normally operable hatches as they are on many boats.

twistedtree · Oct 31, 2019

wkearney99 said:
I saw your ER door on your blog site. Any pix of the laz hatches?

Excellent points about testing emergency exit procedures. It's important to stress the priority is to GET OUT immediately. Not get out with stuff/clothes or without some risk of injury. OUT. NOW.

I’ll try to remember to post some pictures this evening. I’m mobile today getting my FLIBS fix, or perhaps more accurately my FLIBS flogging.

rslifkin · Oct 31, 2019

twistedtree said:
Plus the removable floor sections are pretty big and I expect quite heavy. On our boat they are meant strictly for engine removal and are not normally operable hatches as they are on many boats.

Yeah, equipment removal floor hatches are usually too big / heavy to push open easily (especially if equipment prevents you from getting directly under them). In my case, those are the panels that are trapped under the carpet anyway.

Xsbank · Oct 31, 2019

Why have a latch at all?

OldDan1943 · Oct 31, 2019

I have seen some sailboats that lashed the RIB over the fwd hatch.

wkearney99 · Oct 31, 2019

OldDan1943 said:
I have seen some sailboats that lashed the RIB over the fwd hatch.

I've seen all kinds of boats that make that mistake. Convenience over safety.

Insequent · Oct 31, 2019

A house door latch could work, in brass or SS construction. Easily opened from the inside. Outside it is basically flush with the door (hatch) and key operable. A key could be kept on a hook inside the salon door. A bit inconvenient if opening the cockpit hatch a lot, but I think it would be tolerable. Also, many of these locks can be snubbed back to become the 'no latch at all' scenario Xsbank mentioned. And you still have a lockable entrance to the boat when needed. The key cylinder would need regular waterproof grease....

Something like the Lockwood Nightlatch
https://www.bunnings.com.au/lockwood-brown-100-nightlatch_p4062703

ben2go · Oct 31, 2019

twistedtree said:
I'm trying to find hatch locks that are operable from both sides of the hatch. These are for the hatches in the cockpit floor, leading to the laz below, and are commonly found on many boats. They typically have handles that fold flush to the deck, and that flip up and turn to open the hatch. But they all seem to be operable from the outside only, preventing escape from inside the laz. The dive boat fire in California has me carefully reviewing escape paths on our boat, and getting out via the laz is an important route. Except you can open the hatch from inside.

So the question is whether anyone has or has seen latch mechanisms like this that are operable from both sides? We have found one with an emergency release and have ordered a sample, but for a variety of reasons I an skeptical about how well it will work in practice. Worst case we will station a tool by the exit so the lock can be disassembled, but that's not a desirable approach.

I'd appreciate any leads, and will be scouring FLIBS and METZ over the next days and month..

This is something I was thinking about too. My boat plans show double access hatches in the floor of the pilothouse with a door under the companion way steps, ala sail boat. It would be nice to have the ability to open the hatch(es) from inside the ER if needed. The door under the companion way steps are for pre-trip/pre-start inspections. The pilot house floor hatches are for service and repair work as well as removal of the engine, genset, etc... If something isn't right, it would be nice to pop open a hatch from below without having to leave the ER, reset the companion way steps, open the hatch(es), and crawl down inside the ER. It's a convenience thing for me. I can be a bit impatient and lazy at times.

My idea was to custom fabricate latches out of SS paddle style tool box latches. All that would be needed is a bolt mounted to the back side of the latch slide.

https://www.amazon.com/Buyers-Produ...11624c61a99d60431acbed49f6ff06&language=en_US

Flush mount latch.

Add a bolt to the back of the latch slide.

twistedtree · Oct 31, 2019

OldDan1943 said:
I have seen some sailboats that lashed the RIB over the fwd hatch.

And a really good example of why you need to actually try the escape route and demonstrate it can be done. Casual inspection rarely == reality.

OldDan1943 · Oct 31, 2019

wkearney99 said:
I've seen all kinds of boats that make that mistake. Convenience over safety.

Were the boats named Darwin?

Hatch locks operable from both sides?

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